Summary

A small summary drawing together the most important points.

She cheated before and thought that was her good right, because the guy she cheated supposedly hadn't given her everything she needed. (At the same time she talked down on other people who acted the way she did and said they were 'very special' or 'disgusting')
I offered her an open relationship which she didn't want, because she wanted me only for herself (while she secretly still was with at least one other guy..)
She had cheated that other guy with several guys before me.
She forbade me to talk to new girls, because I would just end up cheating her -> I agreed hoping she would get over that fear of me cheating her as such I was pretty much only able to do things alone or with her(if you meet guys you'll meet girls sooner or later).
She of course had to deal with her other guys too, which left me a lot of time with few options. I used that time to work on things for her..
She kept me a secret from all her friends and family which limited the things we could do together even further.
She always kept the hope alive that things would get better, she'd introduce me to people, she'd get over her problems.
She never even considered to give up her lifestyle, she always planned for eventual discovery, taking care that no evidence of us existed(she is the only one who ever had pictures of us and even pictures with just her on were difficult) always having in mind that I could use such pictures against her. Of course she is right she can't trust anyone doing what she does. She always said if we'd move together she needs room for herself(of course not saying so that she could meet other guys)
Whenever she pretended to do things alone she was with some guy. That was also how she lied about my trips with her to her friends.
She suggested to me to leave Spain together and emigrate which she apparently was planing with other guys too.
She plays the stereotypes of evil cheating guys and innocent girls to manipulate people and abuses people's trust(innocent until proven guilty), although some people simply seem to be completely resilient to seeing the truth. Then she also uses her position as a lawyer to threaten people with the law(and since she is the girl, the bias is always in her favour against guys). She knows exactly how far she can go without getting problems, for example she has no moral calms regarding petty theft.

In short I tried to do everything to support her and help her get better and she was just using me for her own personal gain without the slightest regard to my wellbeing(or the other lives she played with). In the end I took all the damage and she just goes on as if nothing happened(after I confronted her all she cared about was keeping her dirty laundry hidden, she didn't even admit anything to me, when I KNEW) and treats me like I was the one who did the damage. In reality I just miss us and I think things could have been wonderful (and could still be if she really honestly wanted), if she had started to work on her problems and had given us a real chance.