Gettin my x girl back?

I'm trying to find out the best way to get her back, we were best friends for a year (ALOT of history) and then we went out, we went out for like 2months then she broke up with me, well I tryed gettin he back nonstop for like a month then I stoped and long story short she hates me now, doesn't want to see me or talk to me, and she likes another guy, now days I just ignor her and not even pay attention to her and let her do her thing, and it's been 4months, I like her alot and I luv her, I'm a freshman, so please don't tell me there's no way just tell me how I can get her back, the best way, and btw she broke up with me because apperently I was on her to much and annoying, but iv told her I will change and she doesn't beleave it, so help me out here, it's been 5months and I'm still not over her, iv tryed likin other girls but I can't, I can't stop thinkin about her