Death of a friendship *Personal Post, just needed somewhere to vent

Today I ended an 11 year friendship. It's been dieing since October, when she said/did some really hurtful things. It's been on life support ever since, and today I finally decided to pull the plug. People change, I've changed, but she wasn't willing to accept it. Lives get busy, but true friends can meet up after not seeing each other for weeks and pick up just as they left off. We've always had conflicting views on having and maintaining different groups of friends, she pretty much thought it couldn't be done, while I have several groups who I keep in regular contact with. Ever since high school this has been an issue, from when I first extended my friendship circle to include "work friends". And it's just gotten worse from there. If I had previous plans made with one group (usually weeks in advance) but she insisted on calling me that afternoon to make plans, when I declined she would call me a bad friend, and say that I was always picking others over her. It was like being in an abusive relationship. In the last year it's gotten worse, constantly critisizing my school decisions, work decisions, relationship decisions, personal decisions... I couldn't take it. So as the year dragged on I slowly started standing up for myself and made a point to try and get our friendship back on track. That was until my birthday, after everything that had happened, I figured we'd be able to at least have a non-drama filled night for my birthday celebrations. I quickly realized this would not be the case when she came and dropped off her boyfriend at my party, then told me she was literally just dropping him off, and then leaving to go to a different party instead. I was hurt, but didn't want it to ruin my night. Until I later heard that she had told everyone in my kitchen (some of mine and Vincent's friends) that the reason she wasn't staying was because I wasn't a good enough friend to deserve her being there. I was hurt, bad. It wasn't what she said, I've had her say that 100 times before, and then we got over it, but to say it to people in my house on my birthday, instead of just talking to me, was the lowest thing that she has ever done.
For weeks I boiled inside, so angry that she wouldn't just talk to me, everytime I saw her after that she acted like nothing had happened, which would have been the normal course of events had she actually told me... maybe she didn't know I knew, who knows. All I know is that I should have talked to her then, I should have just dealt with it, but I wanted to avoid the conflict. I tried to just cut off all contact, just walk away without explaining. But I caved pretty quick when our other close friend started talking about Christmas, I figured if this was going to be our potentially last Christmas as friends I should maybe try and patch things up, if for no other reason than to make myself feel better. But it did the exact opposite, I felt angrier than ever that she didn't even try to apologize or show any regret for how much she hurt me that night. If I had dealt with it back in November when I should have it wouldn't have been so hard, but after today it was clear.
Today, she invited me to her son's birthday on Saturday, being a super busy month for work (Roll Up The Rim just started) and people (I have 8 close people born within 10 days of each other) I explained that I might be late leaving work, and I'd already made some birthday supper plans weeks ago, so I could come right after work, but leave before they ate dinner. To which she replied "Forget about it, just don't come". I realized in that exact moment, that it was over.  I realized that even if I changed my plans to go to this party it would be the most awkward time to be there with her. There was no way around it, I'd brought myself to a point where I couldn't stop, so I just laid it on the table "Maybe you're right, I hope he has fun. I hope you have a great time. See you around someday. But I'm done." And with that last sentence the friendship died.
She then proceeded to post on facebook about "the bitch move" I had made. So I deleted her, I'm done reading crap written about me, and decided that the drama is over, maybe it was a bitch move, but honestly I am done, I just can't bring myself to care enough to try and salvage it now. What was said has been said, I can't take it back now, and neither can she. I wish her all the happiness, and health in her life, I just won't be in it, and I don't want her to be a part of mine.
So here we are, I'm almost relieved, all that built up animosity is gone. I know it's going to be awkward, we have alot of mutual friends, so we will have no choice but to see each other from time to time. But hopefully we can exchange polite pleasantries, but I'm okay with just ignoring each other for now.
At 22 years old, I'm happy to say, for the first time I'm walking away from the drama instead of being sucked right back in. I just never imagined it would be like this.