So overall, long distance relationships are miserable and take a lot of work. I did the long distance thing through all of undergrad (12 + hour driving distance) and then for the past two years of med school (4 + hour) and finally after all that time we'll be in the same city in a few weeks
Honestly, i'd never recommend anyone to do what we did...but that being said it is totally do-able if you have to. I saw my bf at least once every month in med school, which was actually more than we saw each other in undergrad, and while i studied constantly we were still able to keep in touch. (But to be fair, he probably came to visit me more often then i went to visit him)
My biggest advice is never let a day go by without touching base with each other, even if its just a few minutes to figure out what the other person did that day. The worst part of the long distance thing is feeling like you don't know what's going on with the other person because you're not in the same place, so emails, phone calls, texts, IMs, etc. are key. But at the same time, its important for both you and your significant other to understand that you are in medical school and you can't visit as much as you'd like to. If it's meant to be, it'll be annoying and depressing, but completely possible.
Also, I think you'll notice that many of your classmates will be in long distance relationships starting school...and over the first few months, you'll notice many people will start to break up (at least that was the case at my school). Don't let that get to you, it's easy compare your relationship to other people's relationships.
I know this sounds a little negative, but I think it would be pretty hard to find someone who found a long distance relationship to be easy.