Teen son with autism, adhd, depression and epilepsy

just reaching out.. 

I am not sure where to turn next, my son is 17. He has the following diagnosed conditions; autism. ADHD, depression and epilepsy. He’s not had an easy life, but we are at rock bottom, somehow we kept him in mainstream school but he has now left school mid way through his alevels. He was being billed for being weird, he has now not left home for over two weeks, incredibly depressed and will not leave his bed. He had been on a range of drugs, personally I do not think they have helped, he had been on sertraline  for years, and topirimate for the last two years for his epilepsy. He has lost most of his hair on top, and his specialist and psychologist would not acknowledge he was loosing his hair. He had not eaten a proper meal for over two years, he is skin and bones. He hates me and will not take any advice from me, I suffer with my mental health also and had a breakdown about 6 weeks ago. 
not sure what I am hoping for from posting on here, my wife said to mr I need to accept that he will Kill himself soon and his age expectancy is much lower. I just feel hopeless and alone