It's definitely okay to take mental breaks whenever you can. That's one of the reasons I suggest physical activity so often. Not only does it release toxins from your body, but it also distracts your mind temporarily.
This roller coaster is a long ride, but the hills and valleys tend to spread out and get less drastic with time. I'm almost three years out and still think about the A very frequently, but it doesn't hurt nearly as much these days.
This stuff does get easier to handle with time. Hang in there.