Self respect and self love are crucial.
I can only speak for myself here......
If anyone physically assaulted me while under the influence or not they would be removed from my life. There is no grey area. I would not be with someone who cannot control their emotions and turns to violence. It doesn't matter if I love the person or the person loves me. I love myself more and I will not be abused. There are not any excuses or apologies. That behavior is unacceptable and it is my responsibility to myself and for my safety to remove myself from an abusive situation.
Be a friend to yourself and protect yourself. Would you tell your friend to stay in a relationship that was physically abusive?