Coly, you know how they give people who are deathly allergic to peanut butter microdoses to condition their bodies to handle it as they continually increase the dosage?
I think the pain from this experience is dealt with in the same way. We get these doses of pain and images and we have to learn to harden ourselves to them. In time, seeing the same photo again or hearing another upsetting thing doesn't have the same effect. The new piece sure, that will take us down again, but in time there will be no more new.
Sometimes I force myself to feel the pain of seeing him in person with someone for the first time, having him show up with her at some event for my children, getting the divorce papers in the mail, hearing he's getting remarried and she is taking his last name (which I never did). These things are all speculative now and in the future, but somehow I feel like I'm getting a head start on getting over them so he can't hurt me to the same depth ever again.
My counselor once said instead of focusing on what I missed or was gone, or what would never be, to focus on how unhappy I was in the marriage. You know what? I was really unhappy in the marriage. He never shared anything with me, not feelings, not thoughts, he didn't spontaneously hug me, he never kissed me, he never did anything "just to be nice." If I needed his help with anything I had to ask over and over again and then he treated me like a nag. If I just went ahead and did whatever or had it done, he criticized everything about it. If he was doing anything, I had to be doing something. But he could lay around for hours doing nothing while I worked my butt off. He never helped with the kids. He never showed any interest in what they were doing. He sat in the car during their events, or fell asleep, or listened to his music or read his magazines. If we were in the car, he chose what we would listen to. My point--this guy was a total ahole and there is no reason I should be glamorizing anything about this relationship.
I'm sure your H wasn't as bad (I think I win the chump award for putting up with the shi$$iest behavior for the longest time), but I bet there were things that weren't wine and roses.
I think sometimes you forget you can detach for yourself, and live as if he is never coming back for yourself, and stop looking behind you, but still leave that door slightly ajar in case he ever comes back. You can do it in a way that doesn't keep you trapped in sadness, make you feel like you are walking in quicksand, or make you feel like your heart is in some jar somewhere and you don't know how to find it again.
