Help - feeling lonely in college?

I just started college 2 months ago and I feel like I haven't made any real friends, just friendly acquaintances in my cles. I am not a shy person, I go up to people and strike up conversations, but I don't have anyone to hang out with on weekends or to eat together. Recently I've noticed that people aren't as friendly as they were at the beginning of term, they're forming small cliques, and I'm starting to feel awkward and intruding when I try to talk to people who are hanging out in groups. I've joined 3 clubs and it's always been like this, people are in cliques, when I try to talk to them, they just smile coldly and resume their own conversations, and it's obvious that they don't need any more friends. I'm starting to feel really tired and dejected, and I'm afraid of eating in the dining hall because I'm always the only person who sits alone. What can I do? How can I find a clique of my own and people to hang out with?