Why can't I forgive my husband for cheating on me

I married Silman when I was 23 years old. He worked in Dubai hence the marriage was long distance. It was characterized by arguments, indifference as whenever he came back home for vacations he totally ignored me. He relocated back after 5 years and in the second year after he had relocated to Uganda. He started an affair with a woman who insulted me daily since the affair started. He always gaslighted me into thinking that it was the woman forcing the relationship. The woman sent me a video of the two of them in bed and this is how I confirmed the affair. He has since apologized and alleged that he cut off communication with her. We have 3 children together, however I don't know how to move forward with him, I don't trust him and I feel irritated by alot of what he does. I can't stop thinking about the affair too. Kindly help