I cheated...

I cheated last night with a guy I have known for a while...I am not in love my boyfriend anymore and yes I have told him and he refuses to leave me, I have been trying to get away for over a year now... I don’t want to get the law involved but it’s looking like thats what I’m going to have to do. If I say something about cheating on him I know he will try to fight with this guy, and I came on to him first... I don’t know what to do??? Do I say something do I keep quiet and try to go behind his back and get the law involved?? What do I do? I am so depressed I feel as if I do not deserve what he has did to me, thats why I did it...