Understandable, snowman. You can deal with your position at that time, IF she files.
Let me provide one possible option on the letter you are about to write.
Take away all your frustrations right now about not being able to work through things with her.
Imagine she died. We had a tragic situation last fall on this site, where a member's estranged W committed suicide, just as it appeared there may have been having breakthroughs. The member and his children lost the opportunity to truly express how they felt to this woman who was living in her own private pain.
What if that were you?
How would you write a letter to your W, were she gone from you in that way.
And then, how would you write the letter if you knew this was the last chance you could ever express to her, how you felt and what you would do to change things if you could have one, last chance to be with her.
For a moment... Imagine that...
Write your letter, Snowman. And then be at peace with it, as though it is the last and final time you would ever be able to communicate with your W and let her know how you felt... deep inside your pain...