AOne Particular Thing That's Bothering Me Is A Dark Brown

AOne particular thing that's bothering me is a dark brown spot, about 5mm in size, on the inside of the foreskin of the penis. It's located where the foreskin gets attached to the penis, at the bottom of the head. It seems to be directly above a white chickenpox blister on the penis itself. It doesn't really hurt on its own or when touched from the outside of the foreskin, but when its touched from the inside, even by a drop of water, there is an excruciating pain. The penis head and the veins are swollen, possibly because of the blisters and there is a slight burning sensation. It also seems harder to get an erection.