Hello, first of all I'm sorry if I don't explain everything clear since English is not my native language, but I didn't find many forums like that in my native language. I'm 20 years old and I've been with my girlfriend for 14 months, she is 18. First 3 or 4 months of our relationship were pretty exhausting for me, since it's pretty much a first serious girlfriend, a woman that I'm slowly planning a future with even though I'm still pretty young. She used to be really upset after I had to go to my house and I could see it, it bothered me because I didn't think that is normal, I'm talking about spending like 8-9 hours pretty much every single day (+ hours in school, since we are going to the same class together), yet she still seemed to be REALLY upset when I had to leave her often at 23 pm. I talked to her about it, I said that it's pretty exhausting for me since I don't have any time left for me or to study and I don't think it's healthy for her to be sad all the time and that I will be visiting her and spending time with her tomorrow and she doesn't have to worry. About 1 week after I told her about it and we discussed it, she told me that she got used by her previous boyfriend and maybe that's the case. Now, when she told me about him I got really pissed off and sad, because she told me that she used to have a romance with him when he had another girlfriend, her good friend, and she knew about it. I got really disapointed with her and sad. She told me that they used to kiss behind her back, cuddle when she wasn't around, he was writing her "sweet" little letters, she sent him nude photos of herself. She told me about the situations where she was using her lips to pleasure him and wanted to kiss him, he then used to shove her head between his legs and said not to stop it. Same with anal sex (I don't really know why they decided to have anal sex instead of normal sex, but I assume it was his innitiative), she was pretty scared since it was one of her first steps in sexual life, and even though it hurt her and she told him to stop he came inside of her. Now, things like this are something that disgust me and make me really angry. I think it's because of my brother that is an alcoholic, I've had a pretty tough life, I was raised in a poor family, because my father left us and my parents business died because of it. I often saw my brother spending time with his girlfriend and then bringing other girls to our house, then telling her that he loves her. I got into fights with him, because he used to beat me, that's why I started to train martial arts, I'm not a violent person, I never was, only situations that I wanted to fight with somebody were with my brother when he used to beat my mother, and I did, because I thought that it's my responsibility and no person in the world can hit my mother without killing me first AND when I saw that guy that my current girlfriend were doing all of these things. I confronted him, I was about to punch him because he didn't want to apologize to her, I was so pissed off once in my life on a situation that wasn't caused by my brother, but my girlfriend stopped me, and when I looked at her I realized I don't want to make her upset, and I wanted to act like a man. After we went home she said that she is really proud of me. Now, the sad and angry feelings went away for let's say 3 months - she told me this about 3 or 4 months into our relationship, I confronted him about 8 months into our relationship (he lives in the same city that she used to live and goes there on occasions, now she lives in my city with her parents and her brother). But now I randomly think about it and I just cannot feel jealous, and yes, I understand that she agreed on cheating on her friend, but I'm at that point in our relationship that I completely trust her, I think she is a wonderful woman, very smart, and it teached her a lesson, just like i understood that life isn't perfect, it's hard, and she was really supportive when I told her about situations in my family and still is, we get along really well. However I cannot stop thinking (especially recently) about that guy that used to get into her head, hurt her, hurt his girlfriend, told her things like "Well if you don't come and we won't do that stuff I will be really upset". She got bullied in school, she wasn't popular, I believe that she did this because she saw that he "cared" about her and saw her when others didn't. I'm sorry that I probably wrote like a 1000 words and I could have made it shorter, but as I said, I'm not good at explaining things, I think that  the more I write the better I will feel. I just cannot stop thinking about someone touching her, having sex with her, forcing her to do these things by saying words to make her do it. And I would be completely fine if she was in a normal relationship, because it's normal that you want to do these things with your partner, but something like this is disgusting to me, makes me angry. And even though I think I understand why she did that there's always this thought in my head that she cheated her friend. And there's this thought that some scumbag did something like this to her, I tried to stop thinking about this for a long time, sometimes it even won't let me sleep, because of how emotional I take things. Is there something wrong with me, is it normal that I cannot stop thinking about it, wouldn't a normal man stop? By the way, I really appreciate if someone spent his time on reading this.