Sorry to hear your night didn't end well! I will tell you a story about my first heartbreak and how I look back on it now. Feel free to skip to a more interesting post!
I was 16, he was my best friend for 3 years previous to our short 6 month relationship. I poured those 3 years of emotion into the relationship. I think he was like any other 17 year old, so it was destined not to last!
He broke up with me, not face to face. I felt like my world had ended, it was such a shock.
What got me through was my best friend and her being there for me to cry on, get angry with, and slowly build my life again. It was going through the motions and just functioning that did it and slowly I got my strength back and put the weight back on! (was wearing aged 12 years jeans at one point).
So I would say, cry, shout, or do anything you need to do, but choose a cut of point. You need to allow yourself to feel awful, because an awful thing has happened. But you need to also be aware of what actions are helping you heal and what are not.
When you find yourself in a situation that is making you feel even worse, ask yourself if these actions are making a difference to you moving on. If the answer is no, then allow yourself to stop whatever it is you are doing and choose something constructive.
Take each day as an hour at a time if you have to. Plan things with your friends.
Btw, Mine came running back a year or so later. I wont deny it was tempting, but my strength made me make the right decision. He will always take that position in my life of being the first person to really break my heart. But that is where he will stay.