It's a tough situation to be in, and many people just don't accept same-sex relationships. You may be able to talk to your parents, but they also may not want to listen. There's no easy solution to this, and it really depends on you. It's horrible that you have to be placed in this spot, and it's essentially forcing you to choose between two groups of people that you really care about... and I can't tell you what to do.
For some, the family is extremely important, and if they aren't happy, then they will never be happy themselves. For others, giving up the person that they think they may spend the rest of their lives with is impossible.
I will tell you this... 8 hours apart is extremely difficult. You're both going in to college, and you will bot get the opportunity to meet several new people. And from personal experience, long distance relationships are extremely hard. That doesn't mean it's impossible, mine worked out... but mine was only for 9 months. If you are both starting college... this is a four year commitment (two, if you're going to a two year college). Have you considered what it would be like to be long distance for four years? And when youg et back together, will you guys still be the same as what you remember?
And you may say, "well, I can just transfer schools if it reaches that point", and that's something to consider. But does that school have what you're looking for? Can you transfer your courses? Can you afford to go there? Is that place right for you?
I really want you to consider all of these things. Try not to just think now... but thing in the future. I'm not saying you shouldn't try the relationship, I am saying that you should consider it completely. It's hard... and I'm in no position to tell you what's right for ~you~.
Think about it... seriously think about. Who knows, maybe she is just a great friend to you and your emotions don't extend into that of a relationship. But maybe she's someone that could be a lifelong partner as well. But as I said before, long distance is tough. Love isn't the only thing that will keep the relationship together... it's hard when you can't be together and harder still when you're starting college and you're both going to be developing rapidly and finding out who you are and what you want to do with your life. You may find that during college, you are no longer compatible... you may find that you're closer. Who knows...
Just think it over, that's the best I could tell you :). I wish I had a "this is the right answer" or "do this, and everything will be perfect", but it's not like that. At the end of the day, just try to make the decision you won't regret... or at least the one you'll regret the least :).