yeah Ice it as soon as you get done. Try to do low or none impact cardio for a while. Your feet would be fine if you would have eventually started of slowly and gradually increased your intensity and duration. I see this time and time again among my clients, patients and customers.
Its ok to be gung ho about it, the body just needs time to adapt to any new stress it is under. Given enough time the body can adapt to practically anything.
Look up these two terms, that I will link for you and you will understand better what I am talking ah-boot....LOL
Wolff's Law
http://en.wikipedia.org/wiki/Wolff%27s_law
Davis Law
http://en.wikipedia.org/wiki/Davis%27s_Law