What Causes Small Spot With White Head On Thigh?

Hi, I ve recently found a spot on the front, upper inner part of my thigh. It started off small, but over time it grew bigger. The spot got really big and grew a large white head, I tried to pop it but it looked as though it bled inside, under the skin. There was some clear liquid that came out but as it s healed over, the scan has almost turned black. The spot is very very painful. Me being stupid tried to pick the scab again to make it better, somehow, more clear liquid came out as well as some blood, but it is even more painful and the ho,e where the liqid came out of is rather big. Also I have small white bumps around my groind, should I be worried? What should I do?