Unnecessarily jealous

For some reason I’ve been feeling really bitter and weird because my boyfriend of 10 months is almost 20 and he’s been having sex since he was 14 but I lost my virginity to him. For some reason it really bothers me that he’s had sex with literally like 15 other girls and I’ve never had sex with anyone else and he’s talking about us being together now for the rest of our lives, he’s thinking of us having a future you know, but I’ve never experienced anything other than him and possibly never will if that makes sense? It’s so stupid that it bothers me and I don’t know why it does because he’s amazing but I’m only 17 and I love him dearly but I kind of want to get out there and do my thing rather than settling down already but I feel like it’s driven by the fact that he’s a lot more experienced than I am.. I don’t even know! Isn’t that weird? Does anyone have any advice?