
How very hard for all of you. We've been there but on a very limited scale, my youngest has a learning disability and that combined with her determined (strong-willed) / emotional personality has had it's challenges.
We first had problems in pre-school. The best thing we did was find a pre-school that specialized in learning / social differences. The other school my DD was in would just call for me to come and get her if she had a melt down, it just didn't work at all. The school she went to had very small class sizes and low teacher / student ratios so they were able to handle things at school and helped to teach her how to deal with the frustrations she felt. They also had therapy sessions at school. It was only after we were able to get the behavior under control that we got a good diagnosis.
After 2 1/2 years there she was able to go to public school in 1st grade and although she needs services for her learning disability and has had a few times that she gets frustrated all in all she's done great. I do credit her time in the private school for much of that success.
The school had several students with more severe issues many of them the possible diagnosis' you've been given for your DS. I was the Girl Scout Leader for the school when my DD was there and it could be interesting at times. Many of the parents said that the biggest advanatage to the school was that they had finally found a place where there children could get the attention / help they needed in a school environment.
You might check around and see if they have something similiar in your area, ask the doctors if they have a suggestion. Tuition wasn't cheap but they did have a scholarship program, there were a few kids sent there by their school districts. Something to do with the school district not being able to provide for the child and so subsidized their private school tuition.
Good luck in finding answers.