I don't think feeling abandoned by being left with strangers is unreasonable of you to raise but it does reflect badly on your partner. He was probably catching up with old friends but still, his lack of consideration for you is not good. For the amount of time you were there, even if having a drink every hour or so, that is quite a bit. It was probably ill advised to bring it up when you were both drunk, but you have already acknowledged that, but I agree it was something that needed saying, just not at that moment.
Can I ask if you are both normally verbally aggressive when you argue and has he EVER been physical with you like this before, even if he threw a punch and diverted it at the last moment? Have you after got physically aggressive with him?
But, there is no reason whatsoever to hit someone unless you are protecting yourself and they have struck first and even then, reasonable force only. His behaviour, if as you described, is totally out of order and is not excused by you being tipsy and rough with the suit in the suit carrier.
Sometimes, people strike out in the midst of anger and if they realise it is wrong, inappropriate and take full responsibility for their error of judgement, there is a way back. I have someone in my family who, in a very extreme situation, hit someone, it was not excusable and he owned it and was deeply ashamed. He NEVER made the mistake again. He 100% took responsibility for the stupidity of his actions and learnt from it.
However, if someone strikes out, does not see it as inappropriate nor takes ownership of the massively unreasonable response, then walk away as there is no guarantee they will not do it again because they don't accept it was wrong in the first place. They blame you for their violence.
Its tough but you need to put your physical and emotional wellbeing first.