Please help me

Hi everyone. I am at a complete loss.

My fiancé and I have been together for close to 3 years- with a 5 month separation factored into that time frame. I moved back in with my sister due to issues in our relationship- he wanted to move to a new town that I wasn’t comfortable in, he put a lot of responsibility on me in regards to caring for his 6 year old son and I felt very unappreciative, and he had some very controlling aspects (didn’t like my friends, wanted me around all the time, Would constantly check in on me). So I left. And I started seeing someone else, but then I wanted to work on things with my fiancé because he is a good person and I do love him.

We got back together and I moved to the town he bought a house in. Things have mostly been great. I like our home, I got a great new job, and we are expecting our daughter in February. Everything SHOULD be great. But he still throws in my face ALL THE TIME that I was seeing someone else when we separated. He makes me feel like I have ruined his life. He brings up the past constantly and I can’t get him to move on and realize I am trying to hard to make us work. Last night we even got in a fight because my team at work is wearing pj’s today for Halloween. He literally told me I couldn’t wear that because he wasn’t comfortable with the “unprofessional setting” my job was encouraging.

Mind you, I am 24 weeks pregnant and I’m at my wits end. I want to enjoy my pregnancy and I don’t want my little girl to be born into this negativity. How can I help him move forward from our past before it totally ruins our future?

Thank you....