Help please

Has anyone ever had to leave the father of your child... and you were in a long relationship.. how did you feel? Ive been with my boyfriend for 8 years our daughter is 3. Im 24 years old.. he has done alot and ive said things and its like through out our whole relationship we always had problems... we have been on and off through out the 8 years.. and when i tried to leave him 6 months ago he cried and begged and we got back together on new years and these 4 months its still been issues.. like we dont trust each other, he has been sneaky in the past and lied.. i started talking to someone when i broke up with him 6 months ago but when he begged and cried i took him back.. im tired of all the arguing, etc i just want to be happy but i think about our child.. and how long we have been together im use to him in the house it would just be a big change if we broke up for good ... i think that is why i cant break up with him.. im too use to him..but its like yea he has been trying now and spending time more since he was not before but now that he is finally trying it is like i dont even care anymore..