Just throwing some support your way, by saying good for your son, in making some forward advances! That shows some healthy thinking, by realizing his capabilities, and perhaps he will keep going, when he can feel more pride in his self... and less of a burden on others.
hang in there, it sounds hopeful to me
When my son was evaluated and determined to have a personality disorder which causes him to make a lot of the decisions he does, I had to accept that he is who he is, and I need to most of all, love him for who he is. We all need to feel loved and accepted, especially those who have felt like failures, for most of their lives.
I cannot make my son homeless either. I wish he would someday come to realize that he has a condition and could also get disability, but that is a lot to swallow for someone who is high IQ (and I suspect Adhd)
good wishes, and keep venting and sharing all you want. You are not alone!