I don't want to hate him

Hello, I found out in August of 2022 that my S/O of almost 6 years and father to my child has never been faithful our whole relationship. I have no desire to do anything with him unless it involves our child. his presence makes me angry, sad and sometimes rageful to the point that I am missing time with my child because I don't want to be around S/O.

No matter what I've tried I can't keep my emotions level. I can't figure out how to be excited and happy when he's around. At this point i just need to be okay enough to be able to sit in the same room or have a normal convo with him.