Thin piece of skin stopping the foreskin retracting

Hi I am 14 years old and have a question and my foreskin, I masterbate regularly at least once a day with the foreskin covering the head of my penis I do this because I find it more comfortable and cannot pull the foreskin back the whole way while my penis is erect. I decided to see why that occurred, when I pull my foreskin back while erect there is a thin piece of skin attached to the back of the head of the penis, this is what's stopping the foreskin coming down, it is also painful when I try pulling it all the way down while erect. Is this normal to have this  piece of skin stopping the foreskin coming down at an age of nearly 15? And how do I get rid of it please help I am worried about this.