What are your thoughts and experiences with retroactive jealousy? How did you overcome it?

I’m asking sincerely because I’m struggling in my current relationship because of this issue. I’ve already talked about it with my partner, but I still have lingering negative feelings.

The trigger for this jealousy was that my partner and I were chatting about sexual stuff one time. I mentioned something which he found unusual and then basically said it was different with his exes. I feel like this was a neutral observation and there was no bad faith behind it. But I just immediately became so uncomfortable and resentful upon hearing that, that I had to step away from the chat for a while.

I’ve always struggled with retroactive jealousy in dating experiences and I think a lot in the fact that I’ve not had much success in dating until now. I lost my virginity very late in life, to someone who I wasn’t even properly dating. Before that, I had various talking stages/brief situationships that didn’t amount to anything and involved getting played, led on and dumped for a girl that they actually liked and got into a proper relationship with.

So this problem I have is fundamentally rooted in longterm feelings of rejection, inadequacy, and like I’m second-class compared to other women. These feelings have been reinforced by all my experiences with men besides my current partner. And now that I’m in a stable caring relationship with him, it’s still affecting my mindset to the point that I have an internal meltdown upon hearing about exes, especially in a sexual context. :-(

So as per the title…. What are your thoughts and experiences with this problem? If you had retroactive jealousy then how did you overcome it?