What is causing my foot pain and painful lumps on soles of feet?

Fibroma.: From what you describe it sounds like plantar fibroma. Without seeing them its difficult to tell for sure.

Plantar fibromas: Plantar fibromas can be made pain free by shrinking them with interlesional steroid injections.

Many possibilities: Some causes of “lumps” may include: bony overgrowths, soft tissue masses, ganglions, fibromas, cysts, and infection. Have it evaluated by a professional to get the right diagnosis.