Sounds like you may have a self-inflicted hymen injury, especially if it looks like a skin tag on around your vaginal opening. This can occur with any girl or woman but is more likely to occur with women who have thick, "stubborn" hymens. It CAN be remedied by a simple procedure, where your doctor will remove the skin tag and either stitch up or apply a clotting agent to the area. It is relatively painless (I had this procedure done myself, my hymen was thick and stubborn and finally tore all the way during the birth of my first son), as a matter of fact, the only thing remotely painful, for me, at least, was the local anesthetic administered by shot.

If it is not what I described above, I do not have any clue as to what it is, and it would be best to see your doctor anyway, as it seems to be an issue for you. Which I can totally sympathize with you there.