I really need some answers! Why can't I pull my foreskin down?

Phimosis. Ring of foreskin opening is smaller than width of your glans (head) penis. Like trying to push something large through a small hole. Penile frenulum, web of skin on underneath and joining glans, from just under urinary opening to penile shaft may be very tight. One or both of above can explain your problem. Treatment is prescription strength steroid cream or surgery (circumcision or penoplasty).