In no particular order:
Clear out the reminders: Take a look around. See something that reminds you how wrenched you are? Put it in a box. Once you've cleared out everything, put the box in a seldom-used closet, or somewhere else where you won't see it unless you go looking. At the same time, clean, and, if possible, reorganize/rearrange your personal space. Likewise, emails, texts and FB posts. Either delete them, or bundle them all into a a folder, and archive the folder. Change the wallpapers on your phone/computer.
Get busy: Once you've had your fill of wallowing in the pain (and you will, eventually), get yourself out of your usual routines in some way. Take a dance or a language class. Volunteer at a crisis hotline or a soup kitchen or helping kids learn to read. Arrange to be *somewhere* on a regular basis where you can't focus on your pain. An additional plus is that you're likely to find some new social circles to interact with at the same time. Personally, I've found regular, intense, physical activity to be one of the most helpful ways to do this. Physical activity not only brings your focus out of your pain, it gives you all of those lovely endorphins, too. Work up a sweat!
Be kind to yourself: Do nice things for yourself for a while - just like you'd do for a friend convalescing from an illness. Get a massage. A mani/pedi. Spend time on activities that give you joy, however small. Buy yourself some flowers to cheer up your environment. Cook your favorite, healthy meals. If you can, take a trip somewhere distant for a week or two. Have some fun that is all yours.
Try taking a break from being social, even if it's only for a week or two. Do your own thing, be in your own space. Write about your pain (but don't post your writings on social sites or public journals). You may feel more alone/lonely while you're doing this, but trust me, it's better than feeling alone/lonely while you're actually in a group of friends.
Acknowledge: Don't let anyone tell you to just "get over it"...you've sustained a real loss, and trying to diminish that will only make the emotional damage worse. Let yourself grieve the loss. Know that you can get through this.