Geez, that sounds infinitely frustrating!
selling your home to avoid him is a huge move....
Are you guys meeting in person? Or in emails? Emails you can quote him back to him--and say that is what everyone decided.
If you meet at meetings--perhaps they should be recorded or videod--say it's a meeting journal. Then again, you have back up and proof of what was said.
Sounds like he like to railroad folks into compliance with his will, and the other trustees have given up. If you want to fight the good fight--make sure you have back up. And try NOT to let him upset you because this type person feeds on that. That is their power. Don't give it to him.
I can understand being sick of it, though. That type person is an energy-sucker... good luck...