Break up because of drunk night

Just to get things across straight away im not a drinker at all and I'm not violent. But last week me and my girlfriend was having some drinks and I drank nearly half a bottle of 70cl of rum, the next morning my girlfriend told me I was horrible to her, she said I told her were not going to work out, I don't love her anymore, don't want to be with her and that she uses me for lifts, she also said the way I said it I was vile and looked at her like I meant it and then she went upstairs for half hour to cry........ So here's the thing, I can remember alot of the night but everything she told me I can't remember at all, I have never felt any of these feelings because I'm so in love with her I would never want to hurt her. I'm so confused why would I say these things to her if thats not what I feel? And also why can't I remember any of this but remember events that happened before and after?