Oh dear....I'm really not sure!
I don't think running was the best idea though?
I think you need to listen to your body. If it hurts its saying whoa woman, ease up! If you want to go to the gym and work other areas I should think that would be good, but leave your quads until they're better.
Do you have a pool at your gym? That might really do them some good?
Good work on the walking and stretching them out too...maybe have a nice hot radox bath too??
Good luck!! Now I'm off to the gym!!