There may be online support groups, if it's something you're interested in. Either forums like this one, or organized online meetings, where you log in and talk to others.

Can I ask you a question? And I ask this very gently, as someone who's been down a similar road: Do you feel like you have an independent identity? Or is a great deal of your identity wrapped up in what happens with your son?

In the past, I've gotten too wrapped up in other family members' problems, and lost track of myself. Lost track of my own needs and wants, and gotten immersed in their crisis. It's very easy to do. Don't know if that applies to you though.

The last paragraph you wrote was very focused on how he feels and behaves. He's your son, you clearly want him to be happy, and want what's best for him, but are you sacrificing your own peace and comfort because of his condition? YOUR money IS YOUR money- you don't have to buy him anything. And you don't have to feel bad about that. If you CHOOSE to buy him some things, then that is a choice you should feel good about.

It sounds like a very difficult situation. Breaking the anxiety cycle is tough, especially when you have externals that seem to keep pushing it on.