My best friend is a total *****. Help?

I've been best friends with her FOREVER, but for like two years now we havnt really been getting along that well. I've always loved music and it helped me through a lot of hard times, and now she loves every single band i like and tries to say she liked them before me, im just like "okay i dont care?' Well i just went to the glamour kills tour and invited her, i even payed for her ticket and everything. She was supposed to get me a ticket for an All time Low concert dec. 28th, but she "forgot" so now shes going with her friend who shes known for about two months [who DOESNT even like the band] and her friend who shes met once, of course she can buy them tickets. And shes always copying little things i do. Its annoying and shes just a *****. What should i do?