What Is Causing The Blackening Of Skin Around Penis?

Hi, may I answer your health queries right now ? Please type yoI am about 17 years and i masturbate sometimes , maybe about twice to three a week . However , recently the skin around around the peehole of my penis is getting kindda raw and is black in colour , my glans are pretty pink and this comes to a real shock to me . part of the skin area has suddenly turned black and they arent spots , its like a part chunk of the skin turning black and very raw and disgusting looking . I do not feel any pain due to this , but what is going on with me ?! im really panicky as could this be an infection ? due to my masurbation ? By the way , i masturbate with my pillow most of the time, could dat be the cause.. i really need help , pls help someone ur query here...