The worst mistake of my life

I’m in a long distance gay relationship with a woman I love with all of my heart. I’d do anything for her and I’d love to spend the rest of my life with her, but I messed up.

Last night. At a bar. I kissed my ex. Twice. It didn’t mean anything, I don’t know what to do. I immediately realized my mistake and called her when I got home and told her the truth, now things are rocky. At first she said she can’t be my girlfriend, see she’s coming to visit me for the first time in a week. Then we talked it out and she decided to give me a second chance, but things are strange this time. It’s awkward & I don’t know how to act. I can’t eat because I feel sick, and although it hasn’t even been 24 hours, I’m worried beyond compare that she will change her mind for good. Because I know, once a cheater always a cheater- but I swear I’m nothing like that. I also know that it’s not going to be the same, that there’s going to be a lack of trust and loyalty and respect, unless I can fix this and make it change. I know she deserves someone better, someone who she doesn’t have to question if they love her, but I swear I do. I don’t know why I did what I did. I wish I could take it back. I just need to know what should I do?? I can’t force her to stay, but I need to prove to her that’s all it was, was just a dumb irrational choice and that it means absolutely nothing and I love her and I will do anything if that means I can regain her trust in me.