My boyfriend's a player and he told me that if I don't stick around, he'll be looking elsewhere. Help!?

Go ahead, say I'm an idiot because I feel like one. I've been involved in a 3 year relationship with this guy who's a player and manipulator (yes, he's married). We haven't had sex, but we came close. He uses nice words to get to me. I've tried breaking up with him at least 5 times, but every single time, he lured me back in. He told me that if I break up again, he won't have any choice but to seek love elsewhere because he's not satisfied at home. He's a high-profile man in the community and I keep telling myself that if it's not me, it will be someone else so I hang on. Help!!! I seriously need advice.