My son is super emotional and has nearly no self esteem on days like yours too. He hasn't been diagnosed w/ asd yet though.

Gluten free made a huge difference for us but we are still chasing something else. Allergy tests all came back negative but there is some kind of problem....

I always say my sons autism is worse when he is sick and he even regresses some. I think it is the only way they can cope when they r sick

Have you ever tried to eliminate dairy-Casien fom his diet. We have had the same experience with my son. At 3 months we finally figured out one cause was a diary/soy allergy. He tested allergic to them in an allergy test at 4 months we cut out of diet but a trace will still make him have yucky diapers and rash along with more sensory issues and fussiness. He is a mess for 3-4 days after he gets into something We are trying glutten free now and he has started saying a lot of his words again. He is 20 months now-just diagnosed with pdd-nos. I'm not certain the diet will "cure" him but it certainly provides him relief

That would have a lot to do with his diet.