Trying to get over her

Hello I will try and be as brief as I can,
Well I met this woman in 2007 we dated for about 5 months, She was very outgoing fun to be with but some of her behavior was kinda wild and crazy. Lots of drinking and moodiness, It didnt last and we broke up, her the one ending things though, she insisted we remain friends which at the time I felt was a bit odd but I went with it.
she met someone a week after breaking up with me and was calling him the love of her life that week and we reconnected 4 months later and began dating again, that too lasted only a few months with her ending it again.

We stayed friends through the years since and around January of 2013 we started being friends with benefits,we both discussed everything and agreed that neither one of us was looking to date anyone else and if we decided that we were going too we would tell each other and end our fwb.
Around February we were out having some dinner and she told me that she was bipolar, which actually explained a lot of the strange behavior from the time we dated earlier.

I was understanding about it and have always been supportive to her, well as we progressed with our fwb I began to notice some of the same behavior from 2007. She would abuse some of her bipolar meds, over indulge in alcohol which is really bad for people on meds for bipolar. If I did not do everything she wanted to do or stay up as late as she wanted it would always end up with her becoming angry. I have seen her become so enraged at her kids, one of them would say something that was not really that bad and she would just become unhinged and scream so loud using profanity.
I had to say something to her about it but she just would look at me.

She was hypersexual at times honestly a lot of the time, She had maintained friendship with lots of her ex's. I saw a few texts that raised my suspicions one ex texted her asking "what are you wearing"
another texted "so what did you decide".
Two of her friends a couple were after her to have a threesome with them, well one evening she was to meet me and she shows up and tells me that they kept asking her to kiss them as she was leaving to meet me from their place. She tells me "well I said "F" it and threw my bag down and kissed her then the guy said if you kiss her you have to kiss me and she said she did.

Well a few weeks later I get a text that was sent at 3:50 in the morning, I saw it later when I woke up of her at their place with her in a see through body suit sorta like netting you could see that she was naked under it and her hair was messed up.
I sent her a long text telling her what I thought and it was not nice, she insisted that nothing happened that night and that she was just trying it on, I didnt believe her then nor do I now.
I recently brought it up again and she says that she does not even remember the whole thing now.

We kept seeing each other and we went to a hockey game together and on the ride there she says to me well I signed up for a dating site and that she had been talking with someone and was gonna have dinner with him. I didnt understand why because she kept telling me that she was happy with us, well that didnt work out and things between us continued, then a few weeks later i get a call saying I am not on the dating site anymore but a guy that had been emailing wont stop so I am gonna have lunch with him. That too did not work out so things continued and I went on vacation for a week and while I was away I get and email from her saying that she really needs to work part time, and that her brother who is also bipolar tells her he manages a swingers club and that he needs someone to work the counter and check people in.

I could not believe what she was saying I voiced my objections and she worked there two nights anyway. When I returned she said it was just a one time thing which appears to have been however her brother who is quite the low life keeps asking her to bartend at the place.
Well another week or so goes by we spent a saturday afternoon together stayed together till 9 and had a fun day, then the very next day she goes out with her two friends that have been pressuring her for a threesome and while they are out some guy comes up to her and smooth talks her gives her his number and she starts meeting up with him without me knowing about it. And now is dating him.

I know that how we handled the fwb is not how its supposed to work and I know they very rarely ever work anyway. But I felt betrayed by her with the lies that I believe she has told me, I guess I am a bit naive and too trusting.
I am sure I have left some things out but I guess I need to hear from others about her behavior and it not being healthy to have around me. I honestly went into the fwb with her hoping that she made changes in her life and it would turn into a relationship. But all of this bipolar type of actions on her part always gave me pause and I would become guarded.

I admit I am having a hard time with this I still miss her and I dont know why, I figure I will get past this in time, but I dont know why I am having such a hard time with this when I know she is basically toxic for me.
Any comments are welcome thanks for taking the time to read this

Having lost (given up) a great lover the reason we feel the way we do when everything tells us we're better off without them is that liberated people are incredibly desirable. Be it sexually, intellectually, spiritually, people who do things their way and not society's are very attrractive if we're comformist drones. They're like the freed slave going back to the plantation bringing word of how great it is being free. Most of us are so conditioned to regard sexual relationships a certain way that sexually liberated people who have sex at the drop of a hat and do the whole free love thing seem great at the beginning but we only get with them hoping to change to them to how we are. When that doesn't work and they take off we're left with all the usual abandonment issues and feelings of a normal relationship plus the thinking that this great free type person didn't wanna stay with me. It's like saying the free lifestyle isn't for us. And if it's good and attractive to us, but doesn't want us then it's a second slap in the face because of our ego.

Incompatible personality is all it is though. If not ok with FWB, free love, swinging type relationships that's just the way it is. Not your fault, her fault, or anyone else's. Realize to have been happy together would have meant fundamentally changing either you or her and this why she was attractiv would be lost, or who you are would be changed. Changing a person's core values to make a relationship work never works. It simply causes resentment and ultimately destroys the relationship.

My $.02: Trying to be breif and practical. Embrace the pain, get over her and don't ever be drawn back in again. She's badly suited for you, and bad for you. Setting aside (being very generous here) differing views on relationship boundaries and commitment. She knows damn well what you want, and is willing to string you along and use you, knowing that she'll do things that will hurt you. Don't get mad or hate. She is who she is, but quit being a schmuck. It'll get worse before it gets better, but it will get better. Listen to some Gerry Rafferty in the meantime. That always works for me.