Why my penis feel pain after I pull my foreskin down recently?
How old are you?
Until about 16 it is normal for your foreskin to not retract. You NEVER should force it.
There are layers of skin that separate naturally.
The glans (head) is going to be very sensitive. The nerves have been protected your entire life and aren't used to being touched or exposed to the air. Eventually they'll become more used to it.
Hope it helps.
You are blessed with a protective, highly-innervated, erogenous foreskin. Many unforeskinned guys would envy your foreskin. You display great wisdom in wanting to avoid circumcision,
You should thank your parents for protecting your physical integrity. Because of your physical integrity you will be able to have sex the way nature intended it.
You probably need to stretch the tip of your foreskin to make it wider so it won't be tight.