How do I fix this???????

My friend is mad because I seldom talk to her anymore. I don't talk to her that much because when I try, she will get up and walk off while I'm in the middle of saying something or if someone else comes over, I cut off. So, I decided that I'm not going to waist my time plus, she never remember our conversations so if I try and continue one that was cut short, she doesn't remember. The only problem, our mutual friends are taking her side and say I'm the bad guy. How do I salvage my friendship with my other friends and make them realize that I have done nothing wrong?