Yeah, my WH tried to keep me on a seesaw too. I was advised not to pull the trigger - for financial reasons.
It isn't an easy way to go emotionally! In my case we were S, so it was tolerable.
The only saving grace in my scenario was a friend who constantly reminded me that the pain wouldn't stop just because I filed, or on the day of the D, and that I had to - not only herd the ducks - but first I had to find some ducks to herd!
Keep in mind that the back and forth - is not evidence of R. It is likely evidence of trouble in lala land, or a WS who only wants what they can't have. Neither is an appealing situation. It is likely he isn't trying to mess with your mind - but evidence as to how messed up his mind is.