why do you have to apologise ? she had told you her boyfriend was collecting her, so she had made the first decision, you then said you would get the train, its 8pm at night a safe time to leave another person to make her own way home. Did she offer you a lift to the station in her boy friend's car, no she only thought about herself. Pity the boyfriend.
Walk away now, don't contact again and if in a few weeks time she has no one left to go out with and she asks you tell her you are busy you have made new friends now and you have given up drink, do not let her back into your life do you need it ? no of course not.