un-circumsized penis

Yeah I got that stingy feeling too.

The head (glans) is very sensitive because it has always been protected from the outside world by the foreskin. You can apply an oil like olive oil or baby oil. That will allow you to touch the head.
Then you have to start pulling back the foreskin until it stretches enough to be retracted while the penis is hard.
Do not try to force it all at once. Pull it back partially over the head a little every day as far as you can without causing pain. Use oil to let it slide easier.
If the skin should become stuck behind the head, just squeeze the head between your thumb and fingers. This will cause the head to become softer and let the skin return to its normal position.

i am 15 and i cant touch mine either i can pull the foreskin back over the head but cant touch the head. i have read that if u dont clean it it can get infected and so i dont want that and try to clean it but it hurts. and i want to be able to pull me foreskin over my head when i am erect but i cant. and if i can get my forskin over my head when both erect and not erect can i keep it over all the time to make it not hurt anymore?

It is normal for the head to be very tender after you pull your foreskin back for the first time. It will get less sensitive later.

I would not worry about infection. That is a myth put out by doctors who want to sell circumcisions from which they make money.

Keeping your foreskin back all of the time is not a good idea because it increases the risk of paraphimosis.