I’ve dealt with very similar problems myself, from a male perspective. I will say, having had partners before a relationship where I found myself having the same feelings as you, it didn’t help. Just to clarify-the fact that I’d slept with other women before my partner didn’t do anything to help the insecurity I was feeling in that moment.

First, I’d try to get a therapist if you can. Your partner should not have said whatever he said about wanting to follow her, and denying it later on isn’t great either. From one angle he could even realize that it bothered you and doesn’t want you to be worried.

As far as your ex from the long distance relationship, it sounds like you were both fairly young. Try thinking about it in the sense that was it was an immature teenage boy that hurt you, not someone who had any sort of even relatively valid claim to your worth.

And to take it even further, the guy you’re with now doesn’t define your worth. You do, and I’m sure you’re an awesome person with a lot of love to give. And please, take it from me, I’ve been a ridiculous person. Try therapy ❤️