Lump on penis shaft

[Bentley2022]

About 6 months ago I noticed a lump on the shaft of my penis. It can up almost overnight as far as I’m aware and is a couple of millimetres wide. I thought it would have gone by now. Sometimes it is more prominent and firm, other days it can be soft and less noticeable. It doesn’t feel like a hard lump but is occasionally a bit tender (especially if gently squeezed). It has burst occasionally with a small amount of fluid. I assume it is some kind of cyst. It is pinky red, sort of like a small boil but less painful. It would be good to know if I should be worried or just learn to live with it. Thanks