Calus on the bottom of my foot hard to walk severe pain?

Offload area: If you notice redness and swelling see a doctor right away it could be infected. Otherwise offload it with a nonmedicated donut pad. Get a pedicure to shave it, or do it yourself by soaking your foot in warm epsom salt for 10 minutes and then shave it with pediegg or pumice stone.

See Podiatrist: Determine cause of problem and to provide proper treatment which includes but is not limited to removing the callus.