Its probably best to rest for a bit if its really bad and you cant step on your feet to establish a proper running form.
But dont let the bad injuries stop you from doing anything and going all emo mode cuz of it. You can usually do something like swimming or even
walking instead. Remember its normal and dont try to be in the best shape everyday, it will only lead to more pain, just like idealistic thinking. Train smart
Oh yeah also, what i noticed is, usually doing some simple movement helps alot in overcoming an injury, so i wouldn't advise complete inaction.