@ Katherine Reyes,
Weighted Blanket and melatonin is the way to go. With weighted blanket on him he will most likely tolerate and both of you will enjoy. Reading a devotional to have clam mommie & me time.
Just make sure you get the correct PSI evenly distributed in blanket and it's only 5 to 10 % of his body weight. Too much or little can actually back fire. Talk with your OT to see what weight or % they recommend. It will depend on how much deep pressure he needs. Also be mindful of, if he sweat or gets extra hot at night or too cold. Because you will want to have it made according to that and his tactile needs. Then there the washing of it as well.
Good luck and God Bless.
Needie

My son required someone holding him to get to sleep too until he was 9 years old so it took a long time and a lot of lost sleep to get this down.
This is our routine which has worked extremely well. You need a weighted blanket, Liquid melatonin, a timer, and consistency.
1. my son loves sesame street and the Count is one of his favorite characters.
First, bath time: A timer is set to warn him 15 min before...this almost always starts at 6:30p.
2. Bath, then to his room to play on bed with whatever he chooses...maybe vetch, leapster, small dvd player.
3. Set the timer for 15 minutes before first PP. (we do five pp's before sleep to avoid bed wetting)
4. He gets a small snack
5. pp number one happens when timer bell rings. I perform the count routine. "number one pp ah, ah , ah"
6. Set the timer for another 10-15 minutes. This is repeated for 5 pp. (again this was initiated to avoid bed wetting)
7. after number 3 pp, melatonin in liquid form is mixed with orange juice and given with syringe-dose is 2mg. (my son takes all his meds in liquid form because he cannot swallow a pill). He gets 5 "squirts" of water after.
8. Final pp is number 5. Timer is set for each one and it is announced to him.
9. At that time he comes out of room, gives mommy kiss and hug.
10. He comes back onto bed and I lift the cover, wait for him to get underneath and let it drop on top of him, we say a prayer.
*****BIGGEST KEY TO OUR SUCCESS: Weighted blanket to transition from being hugged to sleep, Melatonin, and not deviating from a very predictable precise routine. We never deviate! The only change ever is reducing pp's to 3x if for some reason the night started late.

My son has been to several specialists for what we believe are 7 sleep disorders but 5 are now diagnosed. He needed more sleep than others and they checked for reasons...sleep apnea, etc. He had nights of insomnia and then days where we could not wake him at all. They used melatonin in mcg's .33 and gave it to him 4 hours before bedtime and again 30 min. before bedtime. He was 14 and 170 lbs. They recommended a certain brand they trusted to have the amount of melatonin specifically and we ordered it. It was set to those times as he needed a set routine with lights out at 6:30 and bedtime at 7:30p.m. and wake time at 6:30 in the morning. They said the wake time was critical as letting him sleep more one day and not another would throw off the cycle like he was catipulted half way around the world. This was a team of doctors at Children's hospital and my son was admitted for 10 days to set this up. He had the tests for excessive daytime sleepiness performed after he was on a sleep routine to give him 11hours of sleep and he has that diagnosis too. Upon waking he uses a light box we ordered one on Amazon inexpensive compared to elsewhere. Melatonin is naturally made in your body for sleep and is triggered by the light. When the sun goes down our bodies make melatonin to help us sleep. The lights out before sleep are critical to make your body cooperate and the light box in the morning is to be looked at to get the light deep into the brain to stop melatonin production. (You can use the sun but we don't have it consistent with our school life...etc. The giving him microdoses 4 hours ahead of time is to set the bedtime earlier. Our son stopped taking his 3:30 dose when he began falling asleep by 4:00 or 5:00 and going through automatic behavior...eating dinner by stabbing at the air around his empty plate all while asleep. Now you may not have any sleep disorders but the bedtime routine was set up for my son to sleep 11 hours nights, in order to help him function in the daytime. If your child needs 9 hours then set it from the desired wake up time and always be consistent with the wake time. If you need to change it, it is recommended to do so 15 minutes at a time. I hope this helps. My doctors at some points have prescibed medication to make him sleep in addition to melatonin but he did not think they helped. I believe the routine has been the most helpful. One more thing...no electronics and things like a good book you can't put down (if they are reading themselves) after lights out. You can have a night light and my son used a low light kindle to read light reading in that hour. He likes music but I hate it when he sleeps with the earphones...and can't turn it off.

We created a schedule when my son was young. (Now 14yo). The schedule was mapped out for day before he was old enough for school. Schedule was modified into before/after school.

He likes to know when things are going to happen and we give 5-10 minute transition notice so change is not a surprise. (Teachers give transition notice at school as well.) Here's an example of our schedule. Of course, when he was younger, bedtime was sooner and baths were at night. Now he does a shower in the morning. The schedule is in 30 to 60 minute blocks of time. Snack after school, homework, picks activity, dinner, help clean up, picks activity that may include parent, get ready for bed an hour in advance (PJs, brush teeth, wash face, etc.), story/reading time (He reads by himself now). When younger, he had a stuffed animal that had a repeating tune. (I wish we had thought of playing music like "CrossingShells".) He still comforts himself with a large, soft stuffed animal about half his size in length. He holds it under his arm and it's usually still there when he wakes up. As he became older, the schedule would shift in 15 minute increments over several days until it arrived at the new time period.

@ MAT TEAM
be careful of ordering blanket over Internet. Blankets really need to be customized to the individual person. If you can find someone local that makes them. You should be able to have your child feel of different fabrics and choose colors that are calming for your child. If your child i is a string puller. Keep that in mind when choosing fabrics. You will want to share in the choosing for several reasons. You want it to help your child & want it to last.
I would also suggest if your child needs it to be. Have blanket made of two different fabrics. One side that feels warm for cooler environments. One side that feels cool for warmer environments. I would stay away from characters or colors that excite them. Consider the wear of washing.
Example, I would stay away from flannel because using and washing is going to cause the material to develope little balls. Like cheap sheets do. Unless your child really really likes it because its mostly for sleeping not rubbing. You could get one made with quilted material as well. It's endless picking pretty much. If you can find a local maker that knows what they are doing.
Someone local should be able to let you borrow one for about three nights to see how or if it's gonna work. Before you invest in one. If the person is honest & has good quality blankets. Then they have nothing to hide. If they are ALL about deposit & payment. Not that they shouldn't be up front about cost. It's more of, do you feel like they really want to help your child or just take advantage of your desperation.
I wouldn't get one any larger than a twin for children that are growing. They will out grow the amount of pressure one way or another. There normal growth and/or puberty will cause this. If you are getting one for someone that isn't growing anymore & want to invest in full size. Do not, do not, get it made of 1 full size piece. Have it made in 2 pieces that velcro & have inside latches to make a full. It's not really necessary to have a full size for teen or adult. If you are worried about them getting out from under blanket. My son almost 19 now. Is all over the place without blanket. With blanket, he pretty much wakes in the same position he fell asleep in. Sleeps like rock! He didn't want it 1st time I laid it on him so, I got under twin size with him. It is wide enough for both of us. I don't put anything but a sheet between him & blanket.
Remember, you have to be able to wash it, handle it, travel with it. If you find a maker that tells you this can't be done. I wouldn't buy from someone who isn't thoroughly knowledgeable about the whole process. They should be knowledgeable about Autism, sensory integration, vestibular system, nervous system, tactile sensory, sensory processing, etc. Don't use as bedspread/comforter. I'm thinking constant weight on mattress may not be good for it.
If you need resources to pay for one or want details of our experience & cost my email is, (Email address can only be seen by the question and answer creators)
Needie