Sticky situation, fallen in love with a different man. please help?

So here's the situation. My husband and I for the last 6 months have been really bad. He's abusive mentally as well as physically. About a month ago I met a new Guy and was completely honest from the get go, that I was married and we are going through a seperation and things were very crazy. He is still around and accepts me and loves my son as well. My husband andihave triedcounseling and he isn't changing. He scares me and im afraid to tell him ive met someone else that treat us o much better. We are seperated at the momnt but i still fear what he might do. I need some hlp. Please no rude comments, this is hard enough already