Boyfriends past

I feel like I can’t be the only person dealing with this!! But my significant others sexual history is bothersome to me!

For context we met at the end of 2015! He said he liked me very much and wanted to date however I wasn’t ready at the time and ended up in a on and off relationship with someone else..After that my current boyfriend and I had a “thing” but it wasn’t exclusive he was sleeping with other people and I occasionally slept with another person for the majority of the year in 2016!

In October of 2016 we decided to make things exclusive and not sleep with anyone else and since he says he hasn’t slept with anyone since we have made things exclusive and I believe that is true!

Though years later the past of us being “unloyal” to one another is starting to impact me negatively and I don’t know how to get past it! He technically never did anything wrong as we weren’t actually dating but for some reason years later I feel betrayed 😫

I know he hasn’t betrayed me so why does it feel like he has? It’s impacting my life majorly! Has anyone else dealt with this? Or does anyone have any advise?