He is breathing fine, not taking any other cold meds. He's sleeping well, just restless trying to get to sleep. He is doing a little better now with the irritability. His stomach is better too. I'm a giving him an adult probiotic twice a day, and I will continue to do so after he finishes the antibiotics. Thanks everyone for all the great advice!

Is it the antibiotic, pain, or lack of sleep, I wonder. If he has a sinus infection is he taking any other medications at all, even Afrin nasal spray? I would suspect loss of sleep from having an obstructed airway due to the infection and inflammation and/or side effect of another cold medication or possibly medication interaction. Just a thought.

Yes, I am. He takes probiotics everyday anyway, but I've increased it to twice a day.