I've been reading up on your thread and I feel like we have pretty similar situations. My WW went gradually from "I'm not attracted to you" to ILYBINILWY in about 5 months. The "not attracted" BD bummed me out but didn't really shake me too much. At that point, I felt like we could regain intimacy if we worked on it and things would sort out. When she hit with ILYB... she also said she probably wanted to separate or "non-romantically co-parent) and that's when I fell apart and did every possible--and of course futile--thing to try to fix the relationship. It's really only been in the past several weeks that I've felt like I've begun to have any success distancing and detaching.
Right now, I miss the intimacy of her and I together in our M, but when I look at her, I don't really feel attracted to her and I remind myself that this is the person that fired me as her H and doesn't feel our M is valuable enough to try saving. That makes her much less attractive to me. At this point I am trying to not let myself get angry in reaction to her or let her get under my skin.
Thanks for the kind words and good luck to you! I'm going to keep following your sitch.