I can understand your concern for the numb circular area on the foot. As the lesion is present since a long time without much of the problem so it is nothing to be worried about. But as it is growing in size with numbness so it will be better if the lesion can be analyzed by a dermatologist
for a second opinion
. You can take a multivitamin
tablet containing vitamin B complex and can apply cortisone
cream for the time being period.