What can I do for the pain under the skin from bumps on the bottom of my feet?

Depends on the bumps. Treatment varies depending on the reason of the "bumps". Some may be due to callus build up underlying prominences. Others may be due to skin overgrown due to a skin virus. Other lumps and bumps may be soft tissue overgrowths or tumors. Have the feet looked at to determine the cause of the problem so that it can be addressed properly.