“Stone Bruise” and Knot on Top of Foot

For several weeks I have had discomfort in the ball of my foot.
A friend referred to it as a “stone bruise” (it feels like I am stepping on a stone), probably caused by shoes being too tight.
I have a very short, wide foot so it’s difficult getting shoes that fit.
Now I seem to have a small lump on the top of the same foot, just below the ankle.
Will soaking in hot water (or anything else for that matter) relieve the discomfort?
Thank you.