Hi, I'm a 13 year old, uncircumcised. I have been masturbating normally for a long time but I actually just noticed that the pinkish part on the inside of my penis that I think is the foreskin, never bends back when I get erect, and I'm pretty sure it's supposed to. I got erect and tried to pull it back over my shaft, but it looked really wrinkly and disgusting, very unlike the smooth pinkish part that's supposed to bend back. But even when I tried to pull it back, it wouldn't stay and just rolled back up. Even though it looked weird, I tried pulling back more the next time, but hurt a little bit. Also, I do not know if I have too much foreskin or not, but I can definitely feel a solid part in my penis and about 1 cm of stretchy skin above it. Please tell me the problem if there is any and how I can make my foreskin stretch back or remedy the situation. Thank you.