My son is almost 4 and we are struggling with the same thing. His adenoids were blocking 90% of his nasal passages when he would try to sleep, so we had them removed 2 weeks ago and have seen some improvement in his behavior becasue he is more rested, especially in the mornings. I guess what I am getting at is: does your son have any interruptions in his sleep? My doctor recommends no artificial light while trying to sleep. A tree limb scratching the window, or pets can interrupt a sleep cycle.
It sounds like this behavior problem is pretty common. I have recently just been trying to contain, not control, his fits. We stoped eating out so much and stopped taking the kids to the grocery store (I go while they are asleep or in MDO). If for some reason we are in a public place and he throws a fit, I drop everything I am doing and head straight to the car. I can't count how many times I have lost my spot in line over this! We sit in the car until the fit calms down. Sometimes this takes up to 30 min or longer. I offer nothing but a sippy cup (fits can be exhausing). I don't debate, reason, or converse at all during his fit becasue he is completely unreasonable at that point. It is hard becasue baby sister is 21 months and likes to chime in, so sometime I have two of them going at the same time. I do tell my son that even mommy has to obey so he doesn't feel like he is the only one with restrictions. Traffic lights are an example. I tell my son that if Mommy doesn't obey the traffic light, then it can hurt people becasue we might get into a car crash.
One last thing.... I really hate giving my kids medicine, but if my child has a fit that results is extreme redness of the face, puffy eyes, and sweating, I do offer Advil on occasion because I know if I am really upset about something and cry a lot I ALWAYS have a headache afterward.
Anyways, I don't really have an answer. I wish I did!
God bless! Liz