You will be better than ok without him. It may be tough to start with, you may even miss him sometimes even though you know he is a knob. But lean on your family and friends and let them care about you, and one day in the future you will look back and think: "What did I ever see in him?"
I've been there. I had a horrible violent tempered live-in boyfriend for a couple of years in my late teens/early twenties. I look back and just can't understand why I didn't get out of there sooner, or why I ever thought I loved him. I don't recognise the person I was when I was with him. But 10 years later I know I am so much better off without him - and I have a lovely husband now who has never so much as raised his voice at me, much less his hand.
Some men may seem great at first, but actually they are just shits. No decent man would ever just attack a woman. And then to be pleased with himself afterwards and gloat by text? Ugh. He is a disgusting excuse for a human being.
If you can face it, do inform the police - even if you aren't visibly injured - it was his intention to hurt you which counts. Would your friend back you up on what happened? Would the club have security cameras? Did anyone who works in the club (easier to find than a random clubber) see anything? Did you keep the text he sent? Even if it doesn't confirm that he hit you it may still be worth showing police to illustrate your story.
I really don't think you should just let him get away with it. Because what if he does it again? Either to you or to some other poor girl?
Even if the police don't have enough of a case they can actually prosecute, it might still be best to make a report that he has been violent towards you, just so the police are aware - even if they can't do anything.