Study

If your attention is fixed on wanting a girlfriend, you could:

• cancel that wish, as in "OK, I decide I will forget about it during college". I just mention this because I recommended it to another member. My poing is, it's just a choice. A non-questionable decision. You just decide it and cut that possibility, releasing your attention from that possibility.
• work your relationship skills to get a girlfriend.
• the middle ground, fulfilling that wish only in imagination. That doesn't mean masturbating. It just means meditating and visualizing that you have a girlfriend, enjoying the thoughts, sensations and emotions of it inwardly. It's a bit advanced but it's really useful.

That depends on what you really would prefer.

 

Like he said, it's inevitably a choice. It's difficult to make that choice, yes, but just keep at it, keep working on your work. I would highly recommend a hobby that takes you entirely away from yourself and women. Volunteering, working with animals, start going to jazz festivals, art galleries, anything. Colleges are known for clubs and groups, join something that you are interested or at least mildly interested in. It will give you something to think about, something to look forward to, new knowledge and experiences really occupies our mind.