Literally the hrdest part for you will be getting out that door.
Wait till the school breaks up, then do a sixty minute session of either gym/cross training or a run, low speed, flat and off road (nice safe trail to minimise potential injury) and try and remember why you run - because it is enjoyable.
The feeling of relief and smugness you will feel after breaking your spell of apathy will taste a lot better than the guilt.
Its your brain that is sabotaging you and not your injury - so don;t let it win.
Good luck and we have al been there so you are not on your own.