Hello,
This piece of skin can be due to frenulum breve. It is a condition in which the frenulum of the penis is short and restricts the movement of the prepuce, which may interfere with normal sexual activity.It is treated by frenuloplasty, frenectomy, or circumcision for which you have to consult a surgeon or a urologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
It sounds to like you have Phimosis. It's quite common actually. Phimosis is tightening of the foreskine meaning it is often painful to retract the skin.
I think the best option for you is to seek advice from a doctor, then a dermatologist. Circumcision is usually the anwer.
I will give you a tip though - try slowly pulling your foreskin back whilst your bathing. Or even try lubrication. It is probably sore to touch because it is so sensitive as it is constantly covered up.
Are you sexually active?
Adam