I would say Dudes got it. You can confirm that doing things you used to do for fun, you can no longer do without feeling really bad. Whilst it is good at times to push into those negative areas, you cant do it all the time. I think you need to accept where you are at for now, and keep away from doing anything that makes your SA worse. You do need to try to accept it though, if you are always fighting back thinking "I should enjoy this and I'm not" you will never win. Chin up and keep going!
I think we all suffer from a lack of confidence. I've struggled connecting with people since I was young, but the older I get the harder it becomes to rebuild my confidence.
The draining thing you talk about is real. That's why I've pretty much checked out from a social life. I go to work and home home to nothing. Besides a few semi social things I just watch TV, browse the net, and stare at the wall.
Let's face it: We got stuck with bad genes. We're ****ed