My husband just hit me. A slap across the face. Im at a loss what to do. We were quarreling and it just happened. He immediately apologised and said it wont happen again.

I'm sorry that this happened.You need to be strong and you need to to think about things. I think you both need to sit and talk about what's happened but firstly you both need thinking time. If possible, stay at your mum's or friend's place first to cool down first and think through things. After a few days when both of you have calm down and clearer mind, sit down and talk through things. If situation needed, you can seek professional help by going through counselling. I hope things will turn out well with you and your husband.