I'm sorry about your dad. He sounded like a good man.
Keep the same distance from him that he keeps from you. This keeps the pressure off. You, keep working on you.
Maybe he doesn't know himself, if he's gonna file! This is where patience comes in...are you at the point where something needs to happen...one way or the other? If not...then leave it alone.
If you don't want a divorce...then don't file. The ONLY reason to file should be because YOU want a divorce. Don't use it as a tool for something other than that.
That's a good, strong, positive attitude.
It's nice to have friends.
"Always go straight forward, and if you meet the devil, cut him in two and go between the pieces." - William Sturgis, clipper ship captain, 1830's.