as the matter of fact i had the same trouble when i was a pre teen and a teen. Actually my cockhead growned first it was an adult sized cockhead when i was around 11. My father and the familly physician told me to so some streching exercices for at least 6 months. They show me how to deal with it and told me to lubricate my foreskin in order to let my glans out... and avoiding to be circumcized.
Try to relax.. try to force the foreskin a little more further every day... Lubrication helps a lot, but if ur 4 skin is very tight do not force it too much, because u could have trouble to but it over the glans again. Doctors call it ParaPhimosis, that can oblige u having a surgery...
Sometimes it can be hurtfull, but if u want to stay "intact" that worth the pain
u can see why i had to do some streching on my homepage @
http://photox.bigckhead.dyndns.org/sec_sta....php?albid=MjE=
that shows why i had to deal with that kind of technics ...
try every day and try to pull the 4 skin a little further each WEEK... and use lubricant...
In less than a 6 months u won't have the kind of trouble anymore...
If u want some advice u can contact me on my email adress.
Take care of yourself and be self confident.