Writing apology letters. Building connection. Those things are great when you realize you need to be a better husband and your wife is still invested in the MR. Once she says she wants out, those things come across as desperate and pathetic.
Lots of marriage saving advice out there is for fixing your MR when you both still want it fixed. You have to be careful with those tactics for a WAS. MWD advocate DBing because those tactics work when your spouse has already checked out of the MR.
I would not write a letter. If you do I would not give it to her. Detachment, differentiation, 180ing, GAL and being the best you that you can be.
Pursuing, pressuring, trying to control doesn't work. And writing apology letters is pursuit and pressure and could een be controlling if you do it trying to get a particular reaction.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018