RELATIONSHIP ADVICE . SOMEONE HELP ME

Me and my boyfriend just got back together & when we got back together he asked me if I had slept with anyome else during the time we weren’t together. And I told him No bc I was scared that he would leave me or try to get back at me in some kind of way bc of what I did (while we weren’t together) the other morning he went through my phone and he found messages that proved I had did what I did so I just admitted to it and I asked for forgiveness so we could move on. But he’s still trying to make me feel bad about myself and dragging me through the mud saying I’m a liar and I’ll never stop lying but I only lied out of fear that he would leave. He told me that he had gotten someone pregnant when we got back together that night but he was still going back and forth between us while we were on and off. I forgave him for all the times he cheated on me and I never bought them up again . I wasn’t even made long bc I felt that our relationship was more important than that so I forgave him plenty of times. But since I lied about sleeping with someone and he saw messages of me talking to the guy in vulgar ways he’s trying to really get on my case about what I’ve done . When I really just wanna move on . What should I do?