Yesterday I messed up pretty bad, the last couple of days my gf [24] and I m[27] have been having a blast together. So much fun, and happiness of being together in all our quirks. She ordered some delivery and when the guy was outside and couldn't figure out which unit it was, I went to go out. She handed me her phone, since the guy called it and I walked out and I flagged him down. On the walk back, I was getting up the stair well, and remembered her previous ex had liked our photo on Facebook. I was weak, for a moment I forgot how great we were, for a moment I remembered how much pain came from being this happy before. How many lies or misjudgments brought me down to my knees, it was in that sad brief moment I looked through her fb messages between her ex and her. I couldn't trust being this happy, being this vulnerable. Before I realized what I had done, it was too late. I walked in the door and for a good 1 1/2 hour I was in shock, I couldn't believe what I had done. I literally shutdown, my gf tried to console me, and I brought up how her ex liked our recent photo, and that I had thought it didn't effect me but that it was weird. We finished eating and were getting ready for bed, and I told her one of things I loved about her. As I heard her tell me one of the reasons she loved me. Which was how she loves how I talk about things before they become a bigger problems, I broke, I was wanting to tell her the whole time. I said "I fucked up, I'm so sorry, and told her about how for five minutes on the walk back I looked through her phone, and how terribly sorry I was and disappointed in myself." She asked for space, and I went to the couch because at this point I was tearing up, and dying to do anything to take it back. After a period of time, I came back and tried consoling her and to make amends. She wanted sleep, so I gave her space and rolled over as much as it killed me to know that I ever hurt her, and I laid there trying to pull myself together. Morning came, I tried once again when she woke up. She held my hand, I swore to her that I would try my best to never let anything like that happen again. We wrapped around each other, and I made her smile with a joke. Here I am later that day, and I feel awful, ashamed, disappointed, sick to my stomach. I'm so worried that those beautiful moments before might be gone forever. My gf seems alright and we did make up before she left, still I can feel that something is off. That only with some time will I truly be able to forgive myself and allow myself to be that happy again enough to get back to what we had. To show her that we can be that happy together, and have my actions reflect that.