That's a common problem in your age range. Guys hit college age, and, especially if they actually go away to college, figure out that there are enough girls desperate for companionship and validation that they can get sex without any commitment, and they lose all desire to be "tied down' by a relationship. Plus, they're in their sexual peak years.
But not all guys are like that; just nearly all of the popular/attractive ones. Those are the ones you really want, I know, but too many of your gender are willing to give up easy sex to them, so if you won't do the same, they're just going to move on to the next girl who will, and you aren't going to change that about them.
That leaves you with two choices:
- The shy, geeky, or just-not-confident-with-women types of guys, who will appreciate a relationship and a girl to be close with, and have no problem with a relationship. The girl will have to initiate more with these guys, and be more understanding that these guys won't understand many social conventions (you'll have to do some teaching), but they usually make good, loyal, appreciative boyfriends. They'll also be in your age range, and if you're away at school, will be living a similar lifestyle, if that's important to you.
- Older guys. Guys in their late 20s-to-early 30s (and up) will have largely gotten past their self-centered "party phase" of their life, will have gotten established in their careers, and are ready for real relationships. They will actually be MEN at this point, with some experience and wisdom, and can take charge and be leaders. They will probably also have some resources of their own at that point (a car and their own place to live), rather than living carefree off Mom and Dad's money, so they'll appreciate things that younger guys often don't.
If you don't want to be single (and why would you?), pick from one of these two groups. and you'll be able to find what you want. You might even be surprised at how much happier you are compared to what you THOUGHT you wanted...