Hi L.,
First off having a background doesn't mean you'll have the answers - you probably already know this so don't be hard on yourself thinking you should be able to snap your fingers and the answer will happen.
I had the sleep problems with my son. He would not, and I repeat, would not go to sleep unless he was on top of me with both my hand over the top of him. Even then most nights I had to hold him tight as he would still insist on screaming himself to sleep. Like an idiot I thought it was normal till my daughter came along and just slept. Something was off and I knew it...unfortunately I was with someone who didn't want to think there were problems with his son.
First off try giving him a little of your coffee in the morning (flavor it with some creamer) and see what happens. Does he get hyper or does it calm him? My son, who is autistic and probably ADHD, has to drink some coffee in the morning to keep calm and focused (small price for sanity). This can be indicitive of a couple of things: a sleeping disorder, ADHD, learning problems (sounds unrelated but it isn't), or sensitivity issues. The road to answers is long, sleepless, and rewarding.
I would highly recommend asking to see a different doctor (get recommendations on doctors open to behavorial issues from your friends - some believe medicating everything is the answer and some are open to real issues) for a behavorial appointment (must say behavorial appt - these are longer and more in depth). Many WIC offices have behavorial specialists that make home visits to observe your child in their own home to assess if something might need a little extra help (can be attained by calling your health dept.).
I have really been there...I am not saying your son is autistic, not that this is a bad thing because my son is so wonderful, but I am saying that even if they seem unrelated these two areas were areas we had the hardest time with my son (I am talking HOURS AND HOURS of screaming before falling to sleep only to wake up two hours later and repeat it all over). Food can be sensory, textures may bother him, which may require a nutritionalist. Try going back to baby food, only get a processor and cook everything - carrots, chicken, rice - blend it and see if he'll eat it then.
There really are answers, but I think a different doctor and some serious assessment will be the way to them. My son didn't get tested until he was three. He started sleeping through the night for the first time shortly after he started in a special school. He eats like a teenage boy (five bowls of cereal?!?!?). It was the best thing I ever did and I so wish I had done it earlier. If you ever want to email me for additional info or even support or ranting (I'm good for all!) my email is ____@____.com wishes!!
C.