In 2016 my SO left me and got with someone else. 6 months later she came running back to me claiming she missed me and wasn’t happy and I took her back because I was coming from a dark place and was just happy to be living and just neglected to think of what she did to me when I was at my lowest . For some reason I questioned what she did(sexually ). Fast forward 7 years later and I proposed and for some reason all these intrusive thoughts starting flooding my brain and now all I can think of is her with him and how she should would not be here because if he wanted her she would never be here. I feel like I’m just a space holder like I’m not good enough and I’m just a fool . It’s eating up my mental space all day everyday. It’s progressed to being so toxic. I have fits of rage and then there’s time I’m happy and the grage and thoughts come back.I feel like it’s controlling me and everything is falling apart. Sometimes I know it doesn’t matter but other times it really eats at me. Talking to a therapist then psychiatrist. Hope I can over come this.