I woke up today and my penis was sore. I looked at it in the bathroom and noticed that it was puffy and red and sort of hurt to touch. I checked back later today and noticed some part getting darker. It lookes almost like dead skin. It is still puff so I have to pull down on the skin to see where it is darker. Im scared and do not know what to do.

Deep dark reddish purple is blood under the skin. Absolute black is dead skin. I've had dead skin from cellulitis, which is a bacterial infection of the skin that gets in where there is a cut or hole such as from an insect bite, or irritation. It's also possible that you were bit by an insect with a poison, or you are allergic to a certain bug bite. Ingrown hairs are a common cause of infection in the pubic region. You need to see a doctor in case you need an antibiotic. Meanwhile keep clean with plain old soap and water and pat dry.