What can I do for my 18th birthday?

I am absolutely DREADING that day. It's the day I will become an adult and will then have to start taking on adult responsibilities. I don't want to have a party. I do it almost every year and I'm miserable. I don't like spending my birthday with a lot of people, most of them who I don't even talk to that much. What can I do? I'm thinking about doing nothing because I can't be bothered and I'm worried nobody would want to spend it with me. My mom would also freak if I didn't do anything. *sigh* It's not even though I can go out and go to a club because they're all a year younger than me!