I'm sorry about the breakup, we all know it sucks to be heartbroken! It will get better though, and it doesn't take as long as you think. I think the key to getting over a breakup is to keep yourself entertained and just do whatever you want without thinking about it too much. If you want to eat 50 donuts then hell, EAT 50 DONUTS. If cleaning makes you happy, then clean. You get my point! Listen to happy music and if you want, listen to the same song over and over and over if it makes you happy. Music like One Direction and artists like that is typical upbeat happy music just try to prove to yourself that you can have fun and that you're fine even if you're single. Hang out with your friends, have sleepovers and go to the movies and have picnics and go to the beach and just enjoy it! In the beginning it will probably just suck and you'll be super bored but after a while you'll get so distracted by what you're doing you'll have fun anyway. And suddenly you'll be like "hey look, I'm actually fine! Wow!" And yeah
And if you stay up all night, that's okay too. Don't get anxious about it. If you're staying awake all night, try to spend the time doing something you enjoy. Like reading or writing or painting and things like that, that occupy your kind. And listen to music!! Seriously, music is a life saver. Just don't listen to songs that remind you of him. I was a real masochist after my last breakup and I spent a month listening to a song that me and my ex had listened to and I just sat there crying and yeah I don't know why I put myself through that!
I think it's amazing that you have such an understanding for your whole situatio and I really do believe it will make it easier. You know why you're anxious again and you know he was your comfort. You just need to prove to yourself that you can be your own crutch, which you can! And if you feel like you can't be your own crutch right now, go to a friend. If they're not emets they will obviously not understand but they will definitely do their best to help you anyway. Remember that you are not alone, you have friends and family and you have this whole forum