How to get over a break up and still try to co parent?

Partner and I split up a month ago. I struggled the first couple of weeks because I felt so gaslit however this last week I've felt like a weight has been lifted. I went no contact for my own healing purposes but still left a line of communication open incase he needed to get in touch regarding our daughter (20months). He reached out last week to ask if he could see her more often because he can't stick to timescales and rules and he doesn't want to be a shit part time dad, he also apologised (weird for him because he literally does nothing wrong 🙄) I've seen him 3 times this week, he comes to the door, picks up our daughter and leaves. That's fine by me. However as time goes on I'm flooded with past memories and the hatred I feel comes in waves. How can I manage this because I don't want to show him he gets under my skin and keep contact to a minimum, the man is literally a dark cloud. I found out he'd been sending pictures of his cock via Snapchat and also accessing adultwork.com - I'm guessing to use these types of services, this was the final nail in the coffin for me because I've had my suspicions about prostitutes and could never confirm it. We lived together so I think he was using them during working hours. He made out I was absolutely crazy for such a long time and I haven't been!