What Causes Bleeding And Cuts On The Foreskin After Masturbation?

hi...i'm 26 yrs old male and i have foreskin problem...i noticed a slightly abnormal shape of foreskin when i was 14..but apart for shape there was no other uneasiness..i used to masturbate normally...but about an year ago i saw cuts on my foreskin after i masturbated and it bled too...and since then it hurts when i pull back my foreskin..