Try to keep contact with her but if you do actually end up drifting apart don't worry abt it too much. People change and they leave sometimes and there's nothing you can do but that's life and people change so you'll change too and you'll find someone new. Friends will come and go in school, that's just how it is, but it doesn't have to be a bad thing if you don't want it to be.
Just because some people don't appreciate or care about you, doesn't mean no one will. I don't even know you that well but I'm willing to give up my whole life to save yours. I don't care if you look like an alley cat that got into 20 different fights in the span of a day or like a dying blobfish, how someone else looks is none of my business. If I'm like this, someone else out there is too and you just need to find them. There's someone out there who will care about you other than me. You will find someone who cares about you enough but it'll never happen if you give up. You don't wnat to take it but you have to. Things won't get better if you don't try to make them better.
Also totally random question would you call yourself a competitive person?