Best Friend - Time to say goodbye?

I have known Sarah* for over 5 years. When we first met we were mostly just 'partying buddies' but Sarah is a drama queen and soon I was pulled into her very hectic life. I didn't mind at all b/c to be honest, helping her with her problems helped me to keep my mind off missing my boyfriend (who was away in the military). It also helped us to get closer and at that point i really needed a good friend. We were practically inseperable for the entire year, yet we both still had our own lives. Then I got married and moved away for 3 years. We weren't good at keeping in touch, so we grew apart. But last year when I returned home, we got very very close again. We even began referring to each other as sisters rather than friends.

But, within these past few months, we have been fighting non stop. I am desperately trying to find myself and get my act together for my family, but it seems that i just cannot get away from sarah's drama. She has drama with so many people and although she is beautiful and people seem to be drawn to her, she seems to have to put me down to feel better about herself. I gained 15 pounds and she lost a significant amoutn of weight (she is a size 1 now!!). She always points out how small she is. She makes comments about the weight i have gained. And although she has been there for me a lot in the past, in our recent arguments, she has thrown everything that i have confided in her in my face. I admit that in these arguments i have become so heated that i have sunk to nm=ame calling and insults. But her insults are much more than that. she hits below the belt. She criticizes everything i do, but if i say one thing about her she says that i judge her. It has gotten to the point that its all i can think about. I am beginning to think that maybe i am the awful person that she says I am. She says that I am a 2 faced liar who judges everyone. My husband says that she says that about me to make herself feel better about all the problems that she has in her life. My other close friend says we just need to talk, but i am beginning to think that the time to talk has come and gone and myabe its just time to say goodbye.

If anyone has any insight to this, please let me know.

Thank you