I know all of this sux. How do you think you will feel about you actions in the future? Will taking the high road be something you can feel good about? If going through the pictures with her is not something you care to do, is there another option?
As hard as it is to go through these with her, at least she wants to remember these things. That in itself is nice.
That you aren't doing anything for yourself is so not good. Keep in mind it doesn't have to be big, just something to occupy yourself. I go on long walks, do something physical or just get out. I will tell you that early on, I had to force myself to get out some and I still obsessed. Time and practice. I'm sure you're sick of hearing it, but GAL is really the best thing you can do for yourself.