Sounds like you are carrying around a heavy load. I'm really sorry this is making you feel so sad. At least you have discovered PC and people who can appreciate your situation.
First let me say that I've never had to deal with a physical handicap nor have I been close to anyone who was. So what I say may not be very useful.
That said I think we all more or less want the same things.
IMO the first thing you need to deal with is financial independence. That is incredibly empowering for anyone. You know how to learn-- you've proved that already. So now you need to put all your energy into finding what kinds of work are paying in this economy and get retooled if that is necessary. ESL has some wonderful opportunities.
Next you can find areas in which you can be the giver. You are articulate. There are volunteer hotlines which need people. You could be a volunteer tutor to kids too poor to hire one. There are many areas which could gladly use you.
I've never been able to make friends and I still can't but I volunteer as a reading tuor at my grandkids school and try to get kids to do their homework. It wears me out and makes me feel useful. It's a good feeling.
I hope you find the inspiration you need.