Why does he lie....

Dude we have been together 3 years. He has lied so much. He has hurt me so much. This last time we got back together because I’m due with our next daughter in 4 weeks. I honestly believe he will change every single time. I think he’s a master manipulator narcissist. He has changed a lot this time in the sense he helps me out more, he’s very kind (until we fight then he raises his hand like he’s gonna hit me even tho he never has, I get called names... it’s bad) anyway he has been accusing me of lying and cheating so much lately I can’t help but think he’s fucking around. He never has cheated or anything but I’m conflicted on if he feels guilty himself or if he has that bad of anxiety about me. Even though all I’ve done wrong throughout these 3 years is forgive him.

Anyway, one of the things he said when we got back together is no matter what he will be 100% honest with me. I see on his Snapchat all his recommended is girls girls girls girls and so I ask do you watch girls stories on here? (It would honestly hurt my feelings but if he were honest I’m not gonna flip you know?) and he said no he swears on our fucking daughter and this has been for months and months now! Finally yesterday after he accused me of cheating all day I looked through his phone and he had watched so many girls on Snapchat. I asked him about it. He called me a dumbass, crazy, said he’s not lying and I’m probably just using an excuse to go fuck someone else????

Guys I think I need to leave him....I’m just scared cause I don’t want to break up my family. He’s such a good dad but I cant be with someone who lies to me and won’t communicate effectively. I don’t want to share my daughters and have them away from me every other weekend or whatever :’( I don’t want to bring another man into their lives, I don’t want to regret leaving him because I know he CAN be good. Am I just in love with his potential?😢😢😢😢😢 help