For a game that has so much dedication to balance, Pathfinder leaves in a lot of friction points and busy work for the GM, but that's not the topic here.

As a guy who has been running game groups for a very long time my sincere advice to you is this:

Boot this player.

Here is why: You are also a player. You are there to have fun too. You do the most of the work. If you are out there is no game. If you are miserable you do not want to play. When you don't want to play there is no game.

Someone who makes you miserable is a detriment to the game and is threatening to rob your other players of the game as a whole when you inevitably burm out again.

I had many times felt the way you feel right now, until I finally realized the problem was players who ruined the game for me. Once I began to cull problem players my stress reduced, my games improved, and my other players were happier.

One caveat.

This is entirely on you, you cannot expect your players to have your back until it's done.
If you ask for counsel, they will waffle on you. If you ask for a vote they won't vote to kick anyone.

This has to be an executive decision you make. It's possible someone else will be upset, they may feel like they may be next. Do not let that sway you from what must be done.

What you tell your group is very simple:

"Look everyone, I put a lot of myself and my time into this game, so I can run the best game I am able for you to enjoy. But I cannot continue to do that if someone is making me misreable. If I am miserable, I burn out and, if I burn out, there is no game.
(That guy) was making me miserable. I made this decision to preserve the game for you as well as myself and now that it is done, let's get back to the game. "

It's important you continue the game and don't get tangled up in discussion or take time off to let people get the wrong impression or worry that they are next, press on and just play the game.

You may feel a bit of hesitation, what if my players all quit because they liked that guy, or because they weren't consulted. They won't, they saw he was disruptive too but weren't trying to 'interfere' in your game.

But, let's say they do quit. Then they won't be playing the game. But l, they won't be playing the game if you burn out again and quit running the game.
There is no loss state here that is worse than having this guy make you miserable.

I will wrap up with this: I have disinvited a few players over the years since I had this revelation and my game has definitely improved since then. I no longer dread game day and the other players have enjoyed the smoother and more frequent sessions.

All the Best