Need help with my social anxiety?

My mom won't take me to see anyone about it so this is my only option. I want to make more friends because at the moment I only have two. It seems as if each day I get even more shy. My confidence level is also dropping. This is my last year in high school and I want it to be fun and memorable. I don't want my social anxiety to ruin it. People also mistake me for being conceited so a lot don't like me. I don't want it to be that way because I'm not conceited at all. Just extremely shy. I have a facebook, but no one talks to me on there so I play online games and chat with people I don't even know so I won't be so lonely during the summer and during school. I've been trying to fix this ever since I started middle school which was almost seven years ago. This year I want to change and be a fun person to be around. I'm really afraid of being myself around people other than the two friends I have. If I get rejected by someone I'm afraid of how that's going to affect me. Anyone have any advice? Oh and I talked to my parents so many times about this, but they just tell me it's no big deal. They're really outgoing though so I'm guessing they don't know what it's like to experience social anxiety. For me it's a big deal, but I really want to get over this and learn to be myself no matter who I'm around. Please no silly answers. This is getting to be a serious issue for me.