Ok, so I relate a lot to the things that you are saying. You should do some reading on Cognitive Distortions because you likely have quite a few of them. CBT therapy might help you overcome at least a few of them.

Along with social anxiety, you might want to read a bit about Avoidant Personality Disorder. They have a lot of similarities. But really, only a professional can help you determine what.

I will, however, reiterate what Trippin said: you can't read their minds. So, no matter what has happened in the past... you can't judge new people based on other people. You can't read their minds and you will interpret everything that the say, do, or simply look... you'll get those things to agree with your own negative bias about yourself because you're so sure that you know what they really think. Try noticing those thoughts when you have them, and challenge it. "That person hates me... why do I think they hate me? They aren't smiling when I smiled. Oh... that doesn't mean that they hate me... maybe they're just in a bad moor or thinking hard about something."