Just suck it up, stick with it and never give up on the job just cause you had a bad day.
Remember, people when they first meet you will not know you have SA. They will not know you have problems talking to people till about maybe the third week when you're still acting shy. Try to talk when people say hi to you. Just a hi or a smile or something. If people say something in a sarcastic way, just make a big grin, brush it off and dont worry about it. Just do the best you can at the job you are given REGARDLESS of how you feel. They'll at least know you're a good worker and don't complain about the overtime or extra work if you have any. Its easy to be a complainer and no one likes complainers.
And don't be obnoxious and annoying like everyone else. Sure people can be assholes but unless you can hold yourself and be an asshole while joking, ok. But dont just be an asshole and brag about untrue stuff. Then you don't look like an asshole, you look like a douchebag. There is one guy at work who fits this to a T. He does not have SA but he is a complete douchebag. He's obnoxious, cusses like no tomorrow, brags about everything, thinks hes cool, and he ALWAYS complains. This is the most hated person in the plant. No one likes him period. He'll go up and talk to anyone and as soon as he leaves, everyone starts talking about him. I'm a nice guy and even I can't handle this idiot. Were waiting for the day he's fired. So don't be like that.... Thats bad advice IMO.
Anyway, just try to test yourself every day and if you can't one day, don't give up. You can try and practice your social skills the next day. And stay positive regardless (easier said than done, trust me but I'm sure you know that anyway). I've just finished up two years at my job going on 3 now and I am soooooo much farther than I was two years ago. Sure I'm still growing but even people at work notice Im not quite the same person that started two years ago. I can push myself to talk easier, I can hold myself up, joke, etc. Ya when I'm around people I havent had much contact with its harder but still, I may be able to talk with them giving the situatioin. But anyway, ya just stick with it, don't give up, keep trying everyday, and you'll get it but it takes time.... and patience.
You can do it. I hated my job btw when I first started. I wanted to quit after the first week. I thought I was gonna get fired. After three weeks I REALLY hated it, I hated the people (not them personally but just cause I felt they were judging me every moment and though I Was someone who couldn't do anything and hated them for it), I hated the job so much but I stuck with it cause one, I never had a job before. I knew it would be hard to get another job, let alone one that pays this well. My aunt helped me find the job cause I told her a wee bit I was having troubles with myself and her husband knew the manager so I put in an application. I didn't wanna quit after they helped me out a bit. Also, I didn't want to solidify the thoughts I know everyone had in their head (that I couldn't do the job etc). I wanted to prove that I COULD do it. And I did. It was hard but I did.
Anyway... you can do it too if I can