Long distance to even longer

I’ve been with my gf for 2 years and half. It’s me and her first serious relationship. And she’s going to college and I’m worried maybe she’s meet someone better or maybe I should let her go so she can grow as her own Person and I do too I have two more years of high school and she’s leaving soon. Idk should I see where we go or end it before she goes? I mean I love this girl to death and i would do anything for her to be happy but Honestly It’s just been in my mind a lot.