Looking for an opinions on my relationship

I have a question about relationships as I'm super new to them. I've never been in anything serious or done much at all until now. My bf grew up in the city and his "kill count" is really high. As I grew up in the country mine is super low. I've only gone all the way with him and his all the way encounters are in the 40s. Don't get me wrong, if I had grown up in a city it would be up right next to if not past his. We're basically the same person. When ever he talks about past people he's hooked up with it make me feel really aweful inside. I've met a couple of his past relationships and hookups and I always get this feeling. I don't want him to stop telling me about everything as I want to know him the best I can and we tell each other absolutely everything. Is it normal to get super down over your bfs past sexual experiences?and what exactly am I feeling here? Jealousy? Hate? Sadness?