I'm not sure how I feel, or is it fear?

I love this person. She's been my best friend since 3rd grade, and around Freshman year I kind of developed feelings for her, but the school we had been going to at the time was very homophobic, and I was moving at the end of the year, so I ended it so they wouldn't make fun of her after I left. The feelings keep returning to plague me, and I want to ask her out again but I'm afraid of again screwing up and this time, I'm terrified we can't stay friends if it doesn't work out. Should I try to daye her again, or should I just stay friends? Like, I want to be able to do all these things with her as her significant other, but then I'm terrified of accidentally losing her because she's always been there for me, and is one of the most wonderful people I've ever known throughout my life. And we have never really fought, ever- we did once in third grade because her family was religious and I wasn't, but that was just kids saying what their parents do, you know? Like, I'm not even 100% sure in what sense it is I love her. Like, I know I'm attracted to her, but I've never put a lot of emphasis on sex in a relationship and as far as I know, she never has been intimate anyway. I plan on moving to Santa Fe with her next summer, so I'll have to wait until then anyway because her family isn't really the kind to be thrilled about homo-relations of any kind.