New to this Community seeking advice

[MichelleLT]

Going dark is a manifestation of letting go.

Writing a good-bye letter can also be a way of letting go.

The question is, what will work best for you? (You, not what you hope will spark some response from her - if you tell her you're letting her go, you have to be able to follow through)

You can always modify Rob's "I get it" speech

"I get it, you haven't wanted to be in this relationship for a long time, that's why you checked out so long ago, that's why you felt it necessary to pursue another man, I get it, I really understand this now. We both did things to contribute to this mess. I just know that now I feel the same way, I finally get it and maybe you should be with the OM because I haven't been getting what I wanted from you in a very long time and I never admitted it to myself and maybe I need to admit to myself that I want to find someone new & exciting to be with, someone who is honest, shares my same values, etc. I hope you and the OM will be happy together because I don't think you really want to be with me anymore and honestly I'm thinking maybe I don't really want to be with you anymore either. My focus right now is to be a great father to my kids and maybe look to start something new with someone new."

You tell her that and mean it, every single word.
Practice it.
Push her to the OM, this shows that you are letting go and moving on, this shows that you've dropped the rope, this shows you're not pursuing anymore, this shows you are moving in the opposite direction and this allows her to pursue you.

No more being an a$$hole, maintain those boundaries, don't let her hit you anymore or use foul language, those are your boundaries. No more relationship talk from your lips, she can talk about the relationship if she wants, you can answer with short succinct answers but that's about it. You don't tell her you love her, you don't tell her you have feelings for her, in fact if she asks, you tell her that are "confused and don't know what you feel anymore with regards to her".

All this time she banks on using the words "I love you", that's the string that she has attached to your heart, she's used it for so long, she knows it works well, you have to show her that it doesn't work anymore but don't push her away brutally, make it more like you finally opened your eyes and realize this isn't what you want, you haven't been acknowledging your needs in a long time (and honestly you haven't, I'm sure the relationship hasn't been all roses up until this point), you need time to discover what you really want, this process has really opened your eyes and made you aware that your needs weren't being met and you are being honest with yourself about this now. You want to find out the great things that life has in store for you and you want her to have a good life even if that means being with the OM, things worked out for the best, etc.

Counter-intuitive.... just like I've mentioned only a billion times on this site.

The OM stuff doesn't apply. In your case, I could see a good-bye letter apologizing for the specific things you did that contributed to the break-up of the marriage. Acknowledging that she felt is necessary to leave. And stating that you will let her go. That you will not stay in a M that she is choosing to keep long-distance and with little communication. That you want and deserve more, so you agree that D is a viable option and you are ready to move on.

A lot of people do see results from a communication like that (a while down the road - my XH took 3 months to absorb the letter and the NC before he wanted to be friends again). But it must be done with NO EXPECTATIONS of R. In fact, it must be done with the full expectation that the next step will be D.

Regarding sending the birthday stuff. It wasn't a 180 it seems to me. You admit birthdays were big, so the 180 would have been ignoring it? Maybe that set you back, maybe not. It was of course a nice and thoughtful thing to do.

The unknown is whether she is receptive.

You have made good changes for yourself, you have been pretty consistent.

At some point, you are going to have to set some more boundaries. How are the finances working out? Did you stick to your boundaries with what you are giving to her for the kids?

I am a full proponent of giving things time to work. That can't be overemphasized. But you have been S a long time, you have been working so hard on yourself. Right now she has the best of everything, the long-distance M with no demands, the kids, the money, but she is not giving in return. At some point, if she is not willing to work on the M, it needs to progress to D.

Filing for D would be one hell of a 180 from you LOL. (I'm not really trying to push you that way, just trying to throw out some ideas, crazy or not, so that you can think about what other 180s you can try).