For me it took years, literally. Probably longer than for anyone on this forum.
I remember back before this forum existed, when my mess began, the advice was also to detach -- I was desperately trying to work out what that was, how to do it, all that. I became frustrated when all my active efforts (GAL, meditation, self-care, etc.) didn't magically result in this state of bliss.
It was a slow, slow process for me, but eventually even I got there, I think.
For me getting to the acceptance of what reality was made the difference; that eventually meant stepping away from my MLCer, but even that took me a long time. Having 3 children with special needs didn't help, I kept wanting him to be involved. I remember when RCR told me to take off the MLC lenses, and look at what was there -- I didn't really want to, because I wanted to see the person that I always believed was the sweetest, kindest person on the planet, but really what I saw was a selfish, entitled mess.
All those things that treasur writes about -- how to reconcile our own stories about life the way it was, about what happened, -- also apply to me. I now think that it is very possible that I had a covert narcissist (or whatever the best description of that is), and that when he broke, it all came flooding out. I remember at the very beginning a therapist telling me that we all have these little selfish tendencies, but normally we keep them in check. He said that "something" (MLC, who knows) in effect "gave him permission" to let that side of himself take over. This could have been temporary, which is why I hung on to MLC as the thing, hoping that it would eventually be over, but in the end every time he could have made the decision to step up, he made the decision to run further.
I had to look at reality, so for me that meant stopping contact.
And since then it's still been a slow process, but I can finally say that my own emotions are no longer tied to his rollercoaster. I'm still sad about it, and still not entirely sure what our life together really was (which is very sad, because I truly loved it, and him), but with that dreaded word, time, I've now built a life that is my own, mine and my children's.
I do now know that what happened was entirely due to what was going on within him, that however imperfect I was, it wasn't about me or our marriage.
So what is now talked about on this forum so much, the acceptance of what is, I think is important. It doesn't mean kicking them to the kerb, it doesn't mean not loving them, but it does mean learning to set boundaries so that we don't go under along with them.
And accepting that it does hurt. It would be odd if it didn't. And it still feels weird when I do hear something, or see a picture, but no longer with the pain.