Sounds like you are both very young, and looking at a long distance relationship when you go off to college.
I know you don't wanna lose her, but College is supposed to be fun and full of experimentation.
If you deny each other this opportunity, it could result in losing her friendship forever.
I think in this situation a more open relationship might help you stay in her life.
But honestly if you're gonna go to different schools, you might wanna consider letting her go. I only say this because LDR's are like hell for both people. Between the jealousy and living apart, you already have some tough issues to deal with and your relationship has to be strong to survive being apart.