Should I just completely end it ?

Okay this might be long lol I've been with my ex fiance for 3 years we have a 2 year old boy and he helped me raise our 6 year old daughter we been fighting a lot and I made the decision to leave for my kids because I didn't want CPS to get involved due to us always fighting well he tells me he still loves me and wants to get back together but that we need to work on ourselves first (that he's tired of fighting and doesn't wanna fight anymore) so were not together right now but he's always texting me asking me what you doing ect and when I post a picture on snapchat or something he says "why so guys can swipe up" but I've seen for a fact that he's been talking to other girls on snap and when I comfort him about it he tells me my attention is always going to be on you your the mother of my kids your always #1 no one can ever replace you blah blah blah but never denys it he always asking me to do stuff for him like if we were still together like he wanted me to file his taxes. I just wanna know if we should just leave it like this and continue it till we fix on our fighting or just end it completely.