I feel so worried about the future for my 4 year old boy. 
Although he is not diagnosed, we do suspect he has high functioning ASD.
A bit of background:
He was a very high needs baby who never slept, moved late but spoke very early.
He stayed at home with me until 3, when he started preschool. He loved preschool but he made no friends and much preferred to do his own thing.
He started school in September and although he is very advanced in his reading and other subjects, socially, things are not so good.
He plays on his own most of the time at break and when he does play with others he tends to think they are being mean in some way. (For example, he came home and said: "They were kicking the ball at me and it was very rude".) It turned out he was in goal... we laughed after but it's happening all the time.
He did have a friend and has had a few play dates which were fine but as soon as he is in a group of people he withdraws.
Recently he has said the boy isn't his friend any more and they've told him he can't be in their club
It seems he's back to being on his own. I'm worried he won't be able to keep friends.
Along with our social worries he is constantly hurting his 1 year old brother. It's like a sudden build up of energy which comes out as hits, kicks, pushing or squeezing. They can be playing perfectly fine together and he will just do it out of nowhere.
We've just enrolled him at a martial arts class to hopefully help with the social side and energy but we are not sure what else we can do.
Sorry for rambling on, I'm not even sure what I'm asking but I guess any advice or tips would be great.
Thanks