I am so sorry for what you are going through right now, my advice will be only to take it little by little, if at any moment during the day you feel hurt, breath! focus on your breathing, deeply and slowly, the most deep and slow breaths you can take, then focus on the things around you, describe them, repeat to yourself where you are at, what are you wearing, and keep breathing, then do something nice for yourself, spoil yourself with something per day, do the things you enjoy and your ex hated, make a list of things you hate about your ex and when you feel sad for missing or feeling you need to contact her /him read that list. you can also write a letter to your best friend explaining him or her why is better to be without that person, that letter at the end it is for you, because you can be your best friend. I hope this help you a little bit and I admire you for leaving that bad relationship. You are in the right way be strong!. hugs for you!