You said this:
If I try to confront him or discuss the problem he gets hostile and deflects the conversation to talk about something trivial that I have done or minimises the problem.
Exactly the same as I went through. Deflection/gas lighting I believe this is called.
I was accused of having affairs with my boss, then one of his friends…. but the flip side reality was that he was seeing someone, so in his head I must have been too.
The thought of having an affair and adding to my lifes drama was about as far from my mind as it could have ever been! I didn’t have the energy to deal with daily tasks, let alone have any inclination to play away!