You can massage your penis with virgin(unrefined) coconut oil. Put one or two fingers in between glans and foreskin. you may try to expand the hoe which is made with foreskin and the glans( not urethra hole through which urine passes.) if you practice for a long time, you may get a normal skin. This condition is called phimosis. If you do not find improvement, visit a surgeon who might do surgery removing your foreskin.Try to avoid surgery as foreskin is important as it has many nerve endings.