I am sorry that you are having a very difficult recovery.
My TKR 12/23 was a personal disaster. I could not sleep, very tight constriction at the joint and severe pain at the lateral side of knee which made walking painful and difficult and stairs impossible.

I understand your depression. My ‘good life’ presurgery was ruined overnight; like going from 60MPH to hitting a wall.

I saw several surgeons and finally obtained a diagnosis of (mid flexion instability) that there was too much laxity in the implant.

I fortunately found a surgeon specializing in revisions and my surgery 4/26 has mostly resolved my knee pain.
I can walk again and stairs are much more manageable.

Do not give up. Find a surgeon specializing in revisions and hopefully you will get significant relief and improvement.