If you can pull the foreskin over the head, you can get it so it will not hurt eventually. Every time you can, like when you are alone in the restroom, pull the foreskin back over the head 9 or 10 times, pulling it back as far as you can, to the point where you can tolerate the discomfort. In a while, you should be able to actually leave the foreskin back for short periods of time, and perhaps even wear it back permanently, if that would be better for you. I wear mine back all the time now, but can easily put it foreward if I want to.