Feeling like I can’t move on from the past

Long (and silly) story: I feel really stupid for having these thoughts, but it’s literally the only thing I think about for the last two weeks. It’s even got to the point I can’t do anything at home and it even keeps me up at night. 6 years ago I broke up with my boyfriend after 3 years of dating because my parents didn’t approve. My parents were having a really hard time back then because of other issues and I didn’t want them to feel more sad (if that makes sense?). So I decided to break up, because “parents know best” and I didn’t want them to be sad. My boyfriend didn’t take it well and we didn’t end on good terms. Some months later I still wondered about him and wanted to connect again with him and try again to convince my parents but he deleted me on all socials (which I understand) so I decided not to bother him, because he probably had moved on. My cousin then introduced me to a friend and we immediately hit it off, everything was going well. Our families met each other and got along. They wanted us to marry quickly, because “everything was perfect”. I agreed to it, because my husband is an amazing person. 3 weeks ago, my friend told me my ex is getting married next month. At first I felt really happy for him hearing this. Then suddenly my friend tells me that my ex told his (ex)best friend that he still regrets our breakup and that I’m still the love of his life. I felt so sad after hearing this and I suddenly remembered all the memories we had together and my feelings for him. It’s now the only thing I think about it and I feel like I ruined my life and made the wrong decision back then. I feel so horrible towards my husband that I’m having these thoughts and don’t want to think about it anymore ‘cause there is nothing do about it anyway. I know it’s in the past and I can’t change that but how can you accept that and move on? I really feel like a bad wife towards my husband and it upsets me so much.