How to not feel jealous/uneasy?

I've been bringing the topic up with him quite a bit even though I don't want to, it just bothers me so it slips out. He had 10+ sex partners and I had 0, and I somehow feel uneasy about it... I don't really understand why, I don't want to be the type of person that is effected by this. 

Sometimes I imagine him having sex with those other people and it's disturbs me and it makes me feel like the sex for him will never be as special as it is for me because he already did it so much. He even said sex has already lost a lot of its charm for him. I also feel jealous that he seemed to have such an exciting life that he'd just "fuck" random girls, I can't imagine that life style it is so different then mine! I also cannot understand how someone can have sex without being seriously emotionally connected to that person... won't he remember all those ladies forever? I wander if he misses them... I feel like I'd be attached to the person I had sex with... I selfishly want him to only know those sexy experiences with me, because I only have mine with him...

He tells me he loves me all the time, and he never brings this stuff up, it's only me that's bothered and so I want to fix that...