Lump under foot

[Savoyafternoon]

I developed a lump under my foot a couple of weeks ago. Not painful but bloody annoying, especially when barefoot.
Does anyone have any idea what it is (feels muscular) and how I can make it go away?
Fingers crossed a picture is attached to show where.

My sister has this . It goes up and down in size depending if she has been standing a long time ( due to her job ) . It’s something to do with her planta fascia. I think it’s called a planta fibroma . She has said that it’s not overly painful but uncomfortable. I know that she massages the tissue around it , rest the foot but stretch the toes back and forth , also stretching the calf muscle too . Other than that if will be resorting to a steroid injection or a topical cream from G. P
Hope you get some relief .🤗

Thank you so much @lovemybooks