Should I keep our friendship going or cal it off?

my best friend and I was hanging for 4 1/2 years. we met in 10th grade we was so close miley and mandy didnt have nothing on us. lol. anyway make a long story short. every since we graduate from high school she dont talk to me like she use too. I thought it was because we go to different colleges but something telling me that's not the reason. anyway, she dated one of her brother friend who use to stay with them and she introduce us and all but we was all cool until she start meeting some of his friends. and she start forgettin about me. she call and tell they all hanging when i call her a week ahead to ask her about us hanging. then when i text her she too busy or she doing something else. but then her and the guy broke up do you guys know she probably call me like one time and didnt call me no more not until this very day. so should i end our friendship or keep it rolling? cuz if we really best friends she would keep in touch