I am hanging in there.
It sounds like your set visit with tickets purchased in advance sounds like the way that you want to go...just as long as YOU want it and do not feel pressured.
You do not need to entertain him the whole time. Set up some pre made plans. You do not have to explain. Go off someplace alone, to walk, breathe, and relax. Then after an hour or two, return refreshed.
Plan outings with him...the movies, shopping, etc., away from home and out on public. There will be less time for conflicts.
It will be good for him to see the new confident you.
Have M spend some time out with him.
Plan breaks for yourself in the visit.
Maybe this will be an opportunity for your son to show that he has changed...a bit. Or, you will show him that he needs to rebuild your relationship and earn your trust.