If I retract my foreskin and touch the tip it hurts terribly. How come?

The glans is very sensitive if it is always covered. It can be so sensitive that it is difficult to clean it or masturbate with the foreskin rolled back. But this is exactly what you have to do. If you touch your glans in spite of the pain the skin will become thicker, which makes the glans a little less sensitive. So you have to roll your foreskin back every day and touch it. You can also expose the glans while you watch television or do your homework. Another way to tackle this problem is to wet the glans with cold tea after showering. The tannic acid will thicken the fragile skin.