Your 3rd paragraph -- I could just copy & paste it right into my thread. Yep, this is all there is, and (except for W divorcing me) I feel so full, so blessed and so satisfied by life; and until the bomb drop I felt like it could only get better as we did more with each other and with our kids.
Where the difference might be in my case vs. yours is that my W not being able to find stability and satisfaction within herself, her falling in love with the act of falling in love itself (rather than the person and the long-term relationship) ... all that is a life-long pattern for her. It's not something that happened just within our marriage. Which is not to say she's always been the same: she did hang in there (hang onto stability) for a long time, but her mid-life physiology and a chance meeting with someone that sparked an EA ... those things kind of put her back on her life-long emotional trajectory.
Anyhow, back to you ... I think you are right that DB/GAL does so little for your W because this is all about her, not you. You could be George Clooney and your W would say she had to fake wanting to hug you. Based on that, I think that detaching and giving her space is the best you can do for her, and -- forgive/forget my hope, but -- I do think there is a modest chance that once she really rolled around in all that freedom she fantasizes about ... and drank in all the sense of meaning and purpose and happiness that comes with that fantasy ... she might realize she's made a big mistake.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final