Am I Wasting Time?!

So I’m 17. I’ve known my boyfriend for 6 years and we’ve been dating for a little under a year. Before we were dating a got around and dated others. I’ve never had this long of a relationship and recently I feel like I’m almost wasting my high school/ early college time with him because I am so young. By that I mean. I could genuinely see myself with him for a long long time. But like I said I’m still young and I don’t want to be held down and risk my future with him if we’re together for awhile (the longer the time spent with someone the more likely they are to cheat especially for high school sweethearts). It’s in my nature to flirt and have fun. I love him but I feel like I need an open relationship until I am old enough to settle down... does any of this make sense? I’d love to know your thoughts!