<human>: Give me the gist of the text in a nutshell

while we were dating, my ex-gf of 5 years went on an away trip to cuba with a bunch of female friends, ended up getting really drunk and slept with a random guy that the girls were drinking with at the hotel. We were deeply in love and had a great relationship before this happened. 

She woke up the next morning and called me immediately, feeling completely terrible about what happened. She has been so so apologetic and heartbroken about this and can't believe she did something like this. She is willing to do whatever it takes to make the relationship work and I do believe she genuinely feels terrible. She says if I take her back she will never travel without me again and will never drink for the rest of her life. Before this she had never done anything remotely deceitful or dishonest. 

I know what she did is terrible and I broke up with her because of it. Its been a few months but I miss her so much. Is one drunken even really a complete deal killer. Does it eliminate 5 years of her being a caring loyal gf? Has anyone else gone through this and got back together? I have self respect, but at the same time I don't want me ego to be what ends up making me decide to leave a good relationship.

I'm considering taking her back, does anyone think that it could work?
<bot>: gf of 5 years cheated during a drunken night away, she feels so terrible and is truly sorry. Is one mistake enough to throw away the whole relationship?