Break up with her and go out and try to meet some new people and see where it goes. Will you regret it? Oh most definitely, probably right away and for a good long while after to. But you’ll have fun once you start to put yourself out there to. You probably won’t get as much sex as you think you will and it will not leave you feeling fulfilled either, but you won’t really understand that until you experience casual sex for yourself. You’ll also learn alot about yourself and grow as an individual by taking some time to be single . You might be thinking “but I still want to be with her” and “i love her so much.” But that doesn’t matter because right now you are not making her feel loved. You are breaking your girlfriends heart by making her feel like she’s not enough and by making your insecurities her problem. Do you think she deserves to be with someone who would tell her that they want to sleep with other people? Do you think she deserves to wonder why her boyfriend doesn’t think she’s enough? Or does she deserves someone who will be happy to stay with her? In the end it’ll be better for the both of you to end the relationship now and not to drag it out, your only making the pain last longer by doing so.