I have a massive problem with my son

Hi everyone

Well once again my problem has raised its ugly head again and i need advice. I am going to be as brief as possible. My son has autism, schizophrenia, epilepsy and a mild to moderate intellectual disability. He lives in about 50% of our world and 50% of his imaginary world. He wants to build these fantastical creatoions to bring his imaginary friends to our world because he says there is a war going on there and they are in danger. He has pages and pages of of drawings of his weaponary which he wants to build which is simply impossible to build by anyone let alone him.

He has been very violent in the past and still hurts himself which has required hospital stays (wont do that again after the last stay). So that brings us to tonight once again he is hurting himself and crying because he wants to build these things .... these fantastical things .... he is so unhappy and frustrated .... I dont know how to help him. We have tried distraction. He goes to day care he is 24. He has a good social life (better than mine)and yet it still comes down to this every night every day.

I am at a loss .... I dont know what to do any more ... Welcome to all suggestions on helping my son,