I think when you have SA, one of the symptoms/sure-signs is the "treadmill of thought" cycle that you're describing Skyla. That often happens to me, I make myself so depressed with my irrational negative thinking. When you start thinking like that, you need to just tell yourself STOP. You need to concentrate on something else or do something - a chore around the house, turn on a TV show, pick up some other hobby, read a book - do something to get your mind focused on something else.
And I know it sucks to be lonely and all - I've had the same feelings. Sometimes it feels like I'm so alone there's nothing left to live for, but I've grown out of that. I have myself to live for and if I can learn to accept myself, that will be good enough. I'll be keeping you in my prayers about getting a new job. I really hope everything works out for you - no one on this board with SA deserves to suffer as much as we do.