1) Cry it out. We all feel emotions, and it's important to let them out.
2) Get ready for a long ride on the "Emotional Roller Coaster Express". You'll feel sad, you'll feel angry, you'll feel stupid, you'll feel frustrated, and then you'll feel better...and... repeat. Your emotions will come and go in a wave of having moments when you feel better, and having moments when you feel horrible, and it is only normal that this lasts a good solid 1-2 weeks.
3) Take time to stay alone, and take time to see friends and family. You need time alone to reflect, feel the emotions, think, and most importantly, rest. Talk to your loved ones when you're ready, and do it in person.
4) Stay away from social media. Just turn your phone off, you don't need to deal with messages asking what happened, nor do you need to already start lurking your ex.
5) Do NOT go out. You will not have fun, drinking is not going to help you in any way, and there is a high chance that you will regret sending those drunk texts.
6) Do not ask to get back together. Yes, you are already missing them. Yes, you are going to think about "trying again". To be honest, I believe getting back together never works in the long run. The damage is done, and it scars BIG TIME. I say: if someone can leave you, they don't truly love you.
7) Take a break from the dating scene. Don't add tinder the next day, you're just going to waste your time, and other people's. And no, hooking up with a stranger is not going to make you feel better.
8) Health first. Wanna know what will ACTUALLY make you feel better? Hitting the gym. You may think chocolate in bed sounds more appealing, but think again. Exercise releases endorphins, and it's a great way to refresh your mind.
9) Avoid contact and delete/unfollow. I won't get too much into this because it definitely deserves a post on its own, but ex's can't be friends, end of story.
10) Don't think you wasted your time. This is a tough one, and I know most people can't help but to feel this way. Just remember you have gone through an experience that can allow you to learn A LOT about yourself, and your behaviours in a relationships. You cannot learn this stuff in any other way than living it, and even the bad experiences are worth your time, because without them, you will not be able to value the good ones.
11) Learn from it. While it's still fresh in your mind, try to understand your relationship from a sort of bird's-eye perspective. What personality traits didn't match? What may have caused unhappiness in both people? Were there signs/red flags? What were the main causes of arguments? How did you communicate? Try to be objective, and most importantly, use your what you've learned.
12) Try again. And maybe again, and again, and again. It may take some longer than others, but true love does exist, and if you want it, you will have it.