Re: severe pain in my foot, cannot walk on it
It is really hard to say, but with it being a week now, and the fact you were moving, going up and down stairs, just maybe you have a stress fracture. I would suggest you go to doctor and get it checked out, something isn't right and you don't want to be falling with your son.
Good luck and let us know what you learn if you go to the doctor.
"Every good has a better and every bad a worse."