I've lost all self confidence?

I've never been a particularly confident person, but the lack of ..Is too much. I even get nervous around my parents. What bothers me more than anything Is that I can't sing when I'm like this, literally can't, just a breath comes out.It sounds silly that whether I can sing or not Is my main concern, but music's the only thing I really love, and if i can't do that then I start to doubt everything. If I do try to make myself spend time around other people I end up covering up how insecure I am by insulting them. I don't like the way I act and can only feel OK when I'm mindlessly clicking on the internet or listening to music. I don't want to feel like this anymore,it really is taking its toll, sometimes I can't stand to even be alone with myself. Sorry If I'm whinging, thanks.