I Think I'm a Sex Addict

So, I'm about to be 19 and I kind of have a problem; I believe I'm addicted to sex. I mean, my current boyfriend doesn't have much of a problem with it, but it seems like some nights I get quite annoying with my "needs" and I usually get pretty frustrated when I don't have sex and sometimes it kind of angers me. It's not like he gets me riled up either, it usually just something that sits on my mind throughout the day and it's kinda like the little devil on your shoulder telling you that you need the thing. 
This "addiction" was the downfall of my previous relationship (one that spanned over four years) and due to him being unable to keep up with my needs, I ended up sleeping with a coworker multiple times. 
I kind of fear that my current relationship will fizzle out and disappear like the last one if I don't get myself into check, but I'm not entirely sure what to do? Like, are there other people on here who have struggled with a sex addiction? Is there a way to control it?
I really love the man I'm with now, but I don't want him to leave me because of this problem that I have; I also don't want to cheat again just to get what I feel like I can't live without.