No need to freak out, but your doctor can remedy this attachment for you. You could schedule a checkup visit and mention this at that time.
The membrane you are describing is normal. It keeps the foreskin in place for a number of years, from babyhood to early adulthood. The age bracket at which the membrane dissolves is pretty wide, like, age 10 - 20. As YardBull says, you could ask your doctor, but probably you are just going to see this change relatively soon and it's not really a problem. You should be able to find some good information about this by googling.