When a runner can't run it has the same effect on you as a bereavement.
When we're subjected to this sort of horrible loss we all go through the same process, we experience:
DENIAL - I'm not injured, I'll run through it, it'll be better tomorrow & i'll be racing at the weekend.
ANGER - Aahh, for f***s sake why does this always happen to me,just when I'm getting fit, lifes's so unfair, Shit. Fuck, Cunt and Arseholes.
DEPRESSION - Right where you are now - poor me, life's awful etc...
ACCEPTANCE - Get some alternative fitness mechanism in place and do something to sort out the problem and get back to running.
These phases don't always progress this way, it's quite possible to slip back from depressed into angry or back from acceptance into depression.
It's a tough sport.