Me personally id leave him. If hes done that the whole time you was together. He will never be trusted. Hes obviously off his head at home messaging these girls.
Whats he said?
Me and my partner both cheated years ago. It just eats you up inside. If we didnt have kids we probably would go are own way. We both still bring things up from 5 to 8 year ago. Its not healthy. So my advice is tell yourself: your better than this and move on !