Same thing happened to me, OP. My advice:
Forgive her, but don't take her back. Forgiveness is not for her her, but for you. That relationship is broken beyond the point of repair. The sooner you can accept that, and forgive her, the sooner you can reclaim your life.
Get rid of everything in your home that reminds you of her. Pictures, objects, whatever. Even if they were gifts.
Avoid certain kinds of media. Overly sad stuff. Anything focusing on a love story. You don't need that sort of thing right now.
Focus on yourself, your own happiness, and your own self-improvement. Hang out with friends. Go for walks in nature. Meditate. Work out. Maybe try a new hobby. Eat healthy food (learning to cook, if you don't already, will go a long way for this).
It's gonna hurt for a while, I won't deny that. Allow yourself time to grieve, but don't get stuck in the mire. You'll make it Anon, I promise.