Why Is The Tip Of The Penis Attached To The Outer Skin?

Sir, i am 21 years old and i haven't had sex. The size of my penis is normal but when i masturbate i see the tip of my penis is attached to the outer skin of it and i cannot pull my skin fully back as i am scared it will hurt. but people say the more you delay having sex the pain will be more unbearable, so do u advice me to do anything and pls if i could avoid circumcision.
Thanks