Feelings of competing

Hey coaches!
So I have run some models on my thoughts here and they are ones that I really wish not to keep. Sometimes when I hear my partner say my ex’s name out loud (or anyone else for that matter) I get a gross feeling in my stomach. It is black, the size of a small rock and I’m now feeling my heart pump out of total discomfort as I write this. Although I know I have nothing to worry about I sometimes feel like I’m competing with Karen (the ex). She was extremely controlling and manipulative, she cheated on him and left. Even after all that, he tried to get her back. Then he met me and the game changed for her. She no longer could control him and tried to break us apart as well. She didn’t want him but didn’t want anyone else to have him either. She tried to use her adult children against me. I remember this one particular time (that I’m obviously still not over) he said he’ll always love her because she’s the mother of his kids and that she was his best friend. (This was two years ago). When we first got together, she would call and talk about her new partner (the one she cheated and left him for) and he would listen! I feel like he might never love me as much as her which I know is silly, and that I still have judgement around him trying to get a woman back who was so awful to him and emotionally abused him. I therefore am judging myself for being with a man who doesn’t love himself enough to stand up for himself. My partner treats me so great and he’s perfect for me but I have this resentment. Does this mean I don’t love myself or that I don’t think I deserve the love of a good man. It’s like I’m somehow making excuses to ruin things which I absolutely don’t want to do. I get those feelings of superiority, that I’m better than him because I would never let someone treat me like that. I am so judgmental right now that I need some guidance. Thanks so much!