Heya Jay!

((((((((((((((((((((((((((((((((( Jaymn ))))))))))))))))))))))))))))))
Yeah, that can be hard..... What I do with my "friend/friends" now is to leave them where they are. (It sounds strange, right?)
Once I call once or twice or so, I let them call me back & if they don't, then we don't talk. It's no skin off my back. That's the attitude I try to have about it--with the reason being THEY ARE NOT MORE IMPORTANT THAN I AM THAT I WILL TAKE CRAP OFF OF THEM. If they're busy, then I'm busy too. Later for them. If they aren't available for me, then I'm not available for them either.
Also, too, check to see what kind of friends you have. What I mean is like I know my Mom will have a friend to go to the movies with, a friend to go out to eat with, work buddies/whatever, a friend she will talk about what really bothers her, etc. It's sort of like there are friends for different things. Sometimes, there are friends who are only fair weather, some who come around only when they want something or when things in their lives are not going as great & need comfort. Figure out what type of friends you have.
I know you've mentioned SA a bit, & I was wondering: Is there a place that you can go where it isn't as bad? (e.g. the library???) I would try to go to that place & cool out there. See who you think is most approachable & see if you can manage a convo. (When I used to go to the library, there were eventually people I would see normally that after a few weeks or so, we'd at least nod to each other or something like that. I found the library non-threatening; that may not work for you, but the point is to find a place that is not too threatening to you to set off your SA very badly.)
The reason I encourage *trying* to see if you can meet other people, as much as you have SA, is that maybe you will find somebody who's on the same plane as you--that treat people similarly to how you treat people. Take little steps, of course, if/when you decide to do it.
If you don't want to do that or even before all of that, what I do is I try to focus on myself more, my life more & where I want to be/how I can get there, see what I can do, or even pick up a hobby of some kind (no matter how simple or great, small or huge, silly or geeky, strange or common).
Something I used to do when I lived elsewhere was go for a walk. I would just walk about by myself, trying to enjoy nature & other things I saw & not bother with people & how they looked at me because they thought I was strange, etc. (I remember one time in my walkabout where I encountered a skunk & had to back away very quickly before I was sprayed.)
I hope I've mentioned some things that can be of help. Hang in there!