Why dose my dmforeskin hurt?

Ignore the circumcised American, they have a circumcision fetish in the US. Your foreskin should NOT hurt either, maybe you rubbed it too hard. See a dermatologist if the skin hurts

girls who know the difference greatly prefer their partners to be circumcised. They know that without a foreskin there will be no nasty smell or taste and that their cannot be any infections lurking under the foreskin to be deposited in their mouth or vagina during sex.

It is possible you have a yeast infection. Yeast infections just happen, and not because you are intact (not circumcised) or not washing properly. (ignore the circumcision responses) They are common in both men and women.
Go to the drug store and look in the men's health aisle for a product to treat Jock Itch. If you cannot find one, go to the women's hygiene aisle and look for a product to treat vaginal yeast infections,.....like Canesten, Monostat, or Vagisil,...they will all work.
Apply the cream under the foreskin and on the glans. If it is a yeast infection, you will notice immediate results.
Continue to apply the cream until the directions tell you to stop,....not just until the redness and soreness disappear, else it will come back with a vengeance.
The second thing it could be in micro tears in the foreskin opening, caused by too aggressive retraction.
If the foreskin is still a bit too tight to easily and painlessly retract, you need to do some gentle stretches in the shower. Let the warm water loosen and relax the skin before stretching. Stretches are to be firm, but gentle, with NO PAIN. Pain is a damage indicator.
Over stretching till it hurts can produce micro tears in the skin opening, that will heal over with non elastic scar tissue, making retraction more difficult. No pain,.....ever.
Good luck, and I hope this helps.
Mithras

You have been exercising it too much.