left foot, ball of foot pain

I have been running for several years and have resently lost more weight and have been running more and completing in races.
About two months ago I started experiencing foot pain in the ball of my foot.
I ran a half marathon and my foot swelled but went down within a day or two.
I went to my physician and he had an xray taken and said no broken bones and said I had inflammed metatarcels.
He gave me some antiflammatories and told me to ice and heat and stop running.
I did as he directed but still have foot pain in the foot.
Especially if I go up on my toes.
Please help before I balloon back up because of lack of exercise.
Sincerely