Pictures trigger feelings of sadness and emptiness

I recently separated from my relationship. I still want to be with him but he isnt sure if he wants to be with me. I am trying to move on and be friends and be thankful for the lessons the relationship taught me. But he texted me some pictures and as soon as I saw his face I felt like I had been kicked in the stomach and wanted to cry. It happened in a second. Because I still love him. When i see he has moved on I take it personally and the pictures confirmed it. I am trying to figure out how to think differently but the triggers are always there.