I need help

I have been with my boyfriend for two years we have a 1 year old kid and have gone through hell and back. I cheated at 6 months and he cheated 3 times 6 weeks after our child was born. After every time we "break up" which he knows I'm going for a drive and coming back, he automatically messages his exs and downloads dating and friends apps. Everytime I come back he tells me he just wants to make friends since our trust in each other is so bad we deleted all social media, cut off friends that weren't both our friends. We really struggle with trust because of all this. More me than him. After I caught him the first time, he lied that he wasn't doing anything and so I made him delete the apps he could contact her with. After that he continued for 2 months even past making my birthday a big bash, I find out he's been downloading the apps and messaging more than just her. I confronted him and he tried to lie but I never got anything but names and him deleting it every night before coming home from work. He makes me feel like he didn't do anything wrong when I know he did it may have been messaging but flirting with your ex fiance that called my unborn child a pedophile. Thats fucked. I dint know if I should could with him since I do love him and I want it to work. But I don't know how to trust him. Especially since he still won't admit he cheated. What do I do.