You are torturing yourself. Please stop placing importance and attention on him! You have no idea how he is coping, he could be very upset inside and dealing with it by getting drunk with his friends to forget.
You are the architect of your own misfortune, you need to place the focus of your life on yourself. Even if you were absolutely right and he was completely over you and didn't think of you one bit (which is pretty unlikely bearing in mind human nature), your obsession with him is making you upset.
The only thing you are in control of in this world is yourself. You can choose to look forward and not back, you can choose to focus on how lucky you are not to be stuck with someone who thinks it's cool to be drinking all night with his friends and post pictures of beer bottles. YOU CAN CHOOSE.
Stop acting like a victim, don't make me come over there and give you a man up pill!
Remember you are a wonderful, caring, kind and good person. You have a superb future ahead of you, this guy was a roadbump on your journey of life and it was a merely a lesson to teach you how powerful and strong you really are. Breathe, focus on you and your life and goals, hang out with your friends, don't talk or think about him (check out my post on thought stoppage to help with that) and live, because every second you waste on his useless ass, is one second of your life you are not getting back.
All the best,