Is it normal to fear speaking this much?

I've been told be countless people to suck it up and just get out there and start talking to people. Every time I do that, it makes me silently fear that they hate me for just talking to them, which makes me depressed, and fear talking more. I don't even let myself enjoy life anymore; I've always felt like my mere happiness pisses people off. I wish I could have fun with my friends, but drawing any attention to myself just gives me a lot of anxiety. If someone compliments my appearance, I'm so afraid of disappointing them later that I end up saying something ridiculously awkward to make them go away. When they leave, it only makes me feel worse, because they looked pissed when they walked off. I have very few friends I can talk too; I avoid any others because I feel that they're annoyed that I'm talking to them, since they could always be talking to someone better.
I'm even failing classes because I'm too scared to present anything, I always think that I'm just wasting everyone's time, and that the don't want me to be here. Hell, it's hard to write this, I'm afraid everyone's going to be pissed at me for asking this question. Does anyone else have to deal with this?