What Is The Treatment For A Pimple On The Foot?

Hello, I have what could appear to be a pimple on the bottom of my foot. It is clearly not a pimple but jus to get an image in your mind. It is small. I appeared at the end of a trip to the beach. I walked probably around 3 miles barefoot on the side of the road, so I though I could ve caught something, cause I went a lotta places barefoot. But I didn t really hurt too much. If I put pressure directly on it it hurts a lot. But jus walking in general doesn t really hurt it. It is slightly red around it, and it isn t an open sore, it s covered with a layer if skin. The skin is if course think on the bottom if my foot. We thought there was something in it like a thorn but I ve cut it open an look an there s nothing. But when I do mess with it so much blood squirts out! But it s fine. I soak in eosin salt. Idk can t find an answer. I ve had it for a month now.