I'm no med student, but am proud to be supporting my girlfriend through her first year of med school. While I rarely see her, I don't complain about it, because I know her not being there is entirely out of her hands. The time she isn't able to spend with me is also time she isn't able to spend with her friends, her family (with whom she's very close), and many more. There can be no room for selfishness in the life of a med student's SO.
What I would say is that the best way to make it work - from your perspective - is to take the occasional moment to acknowledge the sacrifice that he/she puts into the relationship. Let her know that you know it's hard on her. I managed to have a twenty minute chat with my girlfriend on the way home from town this evening, and she acknowledged she was being something of a "crap girlfriend". I don't blame her, nor would I ever want to. It's what's required, and - more's the pity - what's necessary. This made me feel a lot less taken for granted.
Ah yes, the taken for granted factor. Granted, the non-med student girlfriend/boyfriend might not be the one studying horrendously long hours, but equally they're also the ones on their own during that time. It's easy to get swallowed up by the daunting workload around you, but don't let it make you selfish either.
Another thing is to include them in your med school life from time to time. I was introducted to my girlfriend's classmates there for the first time this evening - lovely people, each and every one of them - and it made a big difference to be able to say I've met them and spoken with them. It gives you some insight into their daily life, an insight which the non-med student can't help but wonder about. Given the geographic distance between you and your girlfriend, I would suggest at least explaining to her who your friends are, how you guys spend your sparse free time, and other small things to keep her sense of involvement in your life alive.
From a broader perspective, find value in the brief moments when you do get to see them. It can never be a case of quantity time, so instead make it a case of quality time. The simple truth is that your girlfriend is going to have to learn to appreciate the hastily-stolen five minute phone call, or the occasional spontaneous text. She's also going to need to stay busy herself - I'm a busy career professional training for a marathon, learning to cook, and a whole host of other self-improvement items, but I've joined this site as a means of getting additional insight into what's in store on the road ahead, and how I might make that road less bumpy.
What might seem like abandoment to your girlfriend in any normal relationship, is actually an investment of valuable time on the med student's part. When you do talk to her, be grateful (and she should be the same back). Ultimately, you can only do what you can, and hope that it's enough.
From the sounds of it, a lot of people in my girlfriend's class are breaking up with their signficant others - there's no reason your relationship need go down that path. Keep the lines of trust and communication open, and you'll be in a much better position to weather the storm of tests - both academic and personal.
I wish you the best of luck. 🙂