advice??

so i’m 15 and this girl, her and i dated a few years back in middle school and it didn’t last long cuz it was a middle school relationship, we stayed friends and have been best friends ever since. and i’ve liked her for about a year now. she’s been dating this other girl for 2 years but a couple months ago said she liked me and recently she told me she was in love with me but “can’t break up with her girlfriend” and then we kissed and now she’ll only text me and won’t talk to me in person. and idk if i’m being used and i don’t want to cut her off because she’s been my best friend for years. i don’t know what to do please help :(