Man, I totally know what this feeling is like- I had it all the time freshman year in the dorms. I came from a boarding school for really smart kids, and in college I felt like EVERYONE was a grade A retard. It's hard to realize there actually are other smart, mature people in college besides you... because usually they're not eating in the cafeteria
. My suggestion is check out the clubs on campus, start hanging out in the library or cafe (if your school has one) more, and in general just start talking to people. If you want to meet people who are more like you, you gotta start thinking where they'd be- where would you hang out in a normal day? In your room? In the library? Somewhere random? Sometimes, when I'd be lonely, I'd just wander around the dorms looking for open doors and popping my head in to say "hi." It sounds wierd to say it, but it's a great way to meet people.
College is about socalizing, and it can be hard at first to find people that you really "mesh" with. Don't get discouraged, however. Start talking to people in your classes too- I've met some of my best college friends that way. Chances are, people who are taking the same classes you are are probably going to have some of the same interests you do. Start chatting up people that you notice saying smart things in class- sit beside them every day, start saying "hi" whenever you see them. Everyone in college is trying to make friends, just like you, so if you reach out and make the first connection by saying "hi" whenever you see someone, they'll usually take the bait and start actually talking
Good luck!