im breaking down emotionally.. me and my fiance have been fighting.. but when he fights he is not…

im breaking down emotionally.. me and my fiance have been fighting.. but when he fights he is not fair.. he will come up to my face . in an argument i understand u say mean stuff. but he has slapped me spit on me.. dont worry i got him back for that.. has 3 kids with 2 other women.. so i get aggravated when baby mamas dont keep up with consistency... so i end up spending less and less time with my fiance and more with my 4 month old.. its complicated. i wish i wasnt pushed aside while being smacked at spit on.