My husband thinks I cheated on him

My husband has a “theory” that I cheated on him. He says I’m too busy, questions when I get dressed up for work, travel for work or do anything outside the scope of our home. We have three kids together and I’m the breadwinner of the family. This storyline of his has been going on for four years and during the pandemic, it has evolved to “you cheated on me, but it didn’t work out, so now you are trying to cover it up.” He is very suspicious of me and all my activities.

By nature, I am more of an introvert and keep a lot of my thoughts and feelings to myself. I know I have played a part in this storyline as well, being very reactive and defensive to all of his questions and suspicions about me.

I’m at the point now where I want to focus on my kids, myself and my work. I really don’t want to give any more time or energy to his drama. I want to show up proactive and open. I also want to be compassionate, he is clearly hurting. I just want to fix everything. I want to take care of myself and my kids without hurting him, but I am worn down. I have a physical reaction of my stomach flipping every time he comes home because I don’t want to have any more long drawn out conversations about where I was and what I did.

How do I move through this?