The hardest part of what you are facing is watching them happily walk off into he sunset, with no regard for the wreckage they left behind. It's so hard to wrap your brain around it. You wonder how you went from partner, best friend and lover to invisible in what seems like a moment. The suddenness and unfairness of it is profound.
What I eventually realized was that it was sudden only for me. I didn't even think any of that behavior was possible until I discovered the affair. It wasn't sudden at all for him. The affair had been going on for at least a year when I discovered it. I would later discover that he hit on most of my friends and he cheated on his first wife. He probably had two more affairs, including with the babysitter. He had been lying to me for years, he had been that person all along. I just didn't know or see it yet.
I agree with the previous advice that you need to stop looking at those pictures. Find a way to disable it. It will never help you to look at something you can't fix. If you break something you love and it's beyond repair, you can stare at it until doomsday and nothing will change. It will just keep you in a perpetual state of sadness. Some things can't be fixed and have no explanation, so we have a choice. We can let it freeze us in despair or we can accept it an move to a better place a little at a time. And no, that's not giving up. That's winning.
I know from my own experience with this, when I finally allowed myself to look at who he really was instead of the image I held onto in my head, moving on was easier. He showed me who he was by walking away from my child and I to run off with his best friends wife.
All the dreamy pictures of him and her would never cover up the reality of who both of them really are. I remember how I felt when I found out they had purchased a summer cottage on Lake Michigan while he owed me thousands in child support. That dreamy picture, which killed me at the time, was in fact just a dream. They lost it in foreclosure within 2 years. He lost his good job. She has ended up being the breadwinner, and she cheats on him on a regular basis. I'm sure he's done his share of cheating on her.
If you're like me, as time goes on and you allow yourself to see the real him, you'll look back on things that you remember you thought odd. A remark, a way he looked at one of your friends, money unaccounted for, or time unaccounted for or stories that didn't make sense but weren't worth fighting over at the time. Think about the fact that it could be you who has to live with someone like that for the rest of your life. It will become much easier to find happiness when pondering that life sentence.
