Can you diagnose without a doctor?

by Jessica
(London, Ontario, Canada)

My step son is struggling with many of the issues I've read about here but his Dad doesn't want him tested for anything because he doesn't want him treated differently, problem is, he's already being treated differently.

At ten he still wears sweats to school and big t-shirts because he doesn't like the feel of clothes touching him, he also doesn't like underwear or socks. He touches everything and has to fidget constantly and be loud and disruptive, but not to the point where a friend or teacher would be concerned, they just think he's attention starved and annoying. He's very easily upset or angered but can't communicate anything personal. He has severe issues paying attention, keeping track and count and he cannot handle being alone. He never just walks anywhere, he either stomps, skips or drags his feet, he cannot sit still and likes to tap or bang or hit things for the noise and feel of it. He has no ability to tell when he is full to stop eating so weight is a huge issue for him at home, which probably contributes to the constant overheating and tiring easily but hard to say, he is pretty active. He also seems impervious to pain, likes needles, has broken his arm without so much as a whimper, but freaks out when his sister lightly hits him and insists that it really hurt.

His issues are across the map for the checklist so it's not helpful. Without being able to understand him, he is pushing his friends and siblings and even his parental figures away because they wont put up with him, I don't think he can help it, and I can't get him properly diagnosed so what can I do?