What to do about our long distance relationship?

We've been dating for 14 months and we are way super truly in love. I'm 28 and she is 22. We are so completely right for each other and we always have great adventures together. When I'm with her I feel completely content. She really is the whole package and I am lucky to have her. We have talked a lot about building a future together, but that idea seems to be falling apart.

The problem is that I had to move away six weeks ago for school and now we are 300 miles apart. She is also in college but can't transfer to mine because we are in different types of schools. We can only manage to see each other once every 3 - 6 weeks because of time and monetary constraints. We text throughout the day and make videos for each other on YouTube, but the lack of time together is really taking it's toll. Not to mention that I'm at a school with two girls for every guy, and many of them are pretty attractive so there is a lot of temptation here. I want to make things work with her, but life is pulling me in every other direction. I have no idea what to do. We have talked about it A LOT and she desperately wants to stay together, but I am losing steam fast.

We were together last weekend and everything seemed to be back to normal. We had a great time and I felt really optimistic for a few days after she left, but now I'm back to being full of doubt. I am sure we could have a GREAT life together, but I also believe that I could have a great life with someone else if I chose to. Lots of guys would be lucky to have her, and fair amount of girls would be lucky to have me. I haven't met anyone else at school, but I haven't tried to either.

I was single for almost four years before we started dating, and I was single for three years before dating my last girlfriend. I'm just picky I guess. The point is that I'm afraid we might break up because I am tempted to meet someone else, and then I won't meet anyone for years. My girlfriend is so lovely and patient and understanding, but we'd both be devastated if we lost each other. I don't want to cause all that pain unless there's a real reason to break up, but so far there is not. I love her so much, I just need her to be here and that's not possible.

For now, we have agreed to stay together and try to make it work; at least until one of us meets someone else or we just can't take it anymore. It just seems futile at times.

Any advice or opinions are welcome.