Unreasonable Work Ethic in a work place.

I was recently dismissed and was unfair and for something that went wrong and out of my control.. I also went through lots of personal stress that led to me seeing a councellor with life assist. I telephonically did councelling with Life assist for over 3 months in lock down and in level 2 I met with my councilor. My company's inhouse HR was aware about my councelling. This was a build of work pressure and personal concerns at home. My line manager was aware and did not care two bits what I was going through.. All he cared was work been done and did not care about my health and what I was going through. I am taking this further but with my line manager and not the company..My company was good to me. He was just been a real selfish person and needs to be brought to book.