My watershed moment came after I decided to keep two lists. One for all the times STBE was mean, irrational, difficult, thoughtless, etc. The second for every time he was kind, caring, thoughtful. (And I don’t mean kind in expected ways such as bringing something from the kitchen when he was going anyway.)
That first list was long, quickly. The second still doesn’t have anything on it.
The thing is, if you are contemplating divorce you should probably get one. Good luck.