<s>[INST] Hi I have a hard vein or supply line of some kind in the shaft of my penis that ends just before the head in a lump it hurts when I get an erection and it also pulls my penis in an upside down u shape like a string is tied to the tip that is also very painful [/INST] HelloThanks for query. You have dilated engorged tributary of Dorsal Vein of penis which is painful on erection and tends to curve your glans penis upwards during erection. Please consult qualified Urologist for clinical examination If needed he may advise you to get it ligated and remove the vein. This is simple surgery done under local anesthesia as an out patient procedure and will help to resolve your problem for forever. Chat Doctor.  </s>