Be so anxious

I'd hate to be one of those people who gives themself a self prescribed disease or disorder for attention. But sometimes I feel like me being so nervous and anxious might not be normal. I very rarely make eye contact or speak to the volume that people wont always go "speak up" or "you're so quiet". A lot of times I'm afraid of being looked at or having conversation even with people I've known for a while. I think of bad and embarrassing scenarios and it just makes things worse. If I'd go up in line for lunch I'd like to be in a crowd so people won't look at me alone. I'm only really talkative with close friends and I'm always thinking in my head " don't look at me " or "don't talk to me please" not in a rude way, just because I'd feel really comfortable and self conscious if they did. Is this normal? It's been going on for a few years and I'm 17 now. I've heard that highschool is awkward, but I didn't think it would be to the point where I'm afraid to even walk down a hallway...