I'm finding it really hard to face the world?

I guess that sounds a bit dramatic. But anyway. I'm really shy and have social anxiety. I'm trying to put myself out there a bit more though but it's so tiring. All I want to do is stay at home and avoid all social interaction. I don't enjoy talking to people anymore, my friends want to put me in a box of the timid sort of character but there's more to me than that. To be honest sometimes the world scares me. When I think about the fact I exist I lose sleep over it, the fact that I'm someday going to have to get a proper job after uni.. The next presentation at uni or even catching the bus really makes me dread everything. I have a job interview soon and I'm so scared, I hate having a physical form because it feels like everyone is watching me and judging. I just want to be invisible sometimes. I don't know what's wrong with me. Any help?