been in a long distance relationship for 4 years, and what you're going through is really normal. But here is some suggestion, if you want to stay in your relationship, don't interact with guys the way you would with your bf. In other words, don't get to close because some sort of feeling will develop. Second, if you feel that maybe it's time for a break, let ur bf know in advance. Let him know that you're having these feelings for other guys. It's really a normal thing because you're craving intimacy and you can't have it with your bf right now. So your body is searching for the next best thing: the closest guy within your range...lol...jk, but you get the idea. Talk to your bf. If he doesn't understand, then... at this point, you have to do it for yourself. you guys in college, long distance relationship is the hardest thing to go through. Trust me i've been in for 4 years and I'm 20 now, but somehow I manage to break up with my ex.
Hope this helps.