I got accepted into college, what the fuck do I do now?

So I just found out I got accepted into college but I have no idea what to study.<br><br>I'm an average student and my grades suck so I don't think I could get into any good program. I would like to have a degree in mathematics because I'm relatively good in maths but my grades are bad so I don't think I could get in anywhere. I also don't want to waste my parents money on a useless degree in some random subject. But I kinda don't want to leave school and home because I have no friends and if I leave I won't have anyone to talk to. But I don't want to waste my parents' money on a useless degree.<br><br>I'm really confused and it really sucks. I wish anyone could give any advice.