I Developed A Round Slightly Raised Bump On Bottom Of

I developed a round slightly raised bump on bottom of my foot, originally by the arch/heel. Last night, it changed position to the inner side of my foot. It is red and feels squishy, kind of like a blister, but under my skin. It does not itch all the time, but when it does, nothing works to alleviate the itch. At night when I am laying down, it almost feels as if it's moving or pulsing, and my right foot starts feeling tingly and cold.