I'm sorry you've found yourself in this situation. You didn't mention how long you've been with your partner, not that it matters much, it still hurts--I know. The fact that she is being up front and honest with you now is good. If she's not "in love" with you, the relationship would not be what you want in the end. You love your friends, but you are not in love with them--that's the differance.
You mentioned she doesn't love herself? Until she learns to do that, it will be hard for her to love anyone else. Please try to find something to keep yourself busy like work or a hobby. Do you have some friends you can hang out with, kind of like a support group? You really need your sleep, and I know it will be hard for a while, but the busier you keep yourself the better off you will be. If you need to talk, we are here for you.