I'm 19 year old male living in india, penis head (glans) have black spot and some brown patches, I noticed that 1 year ago but ignore that time. Also I had phimosis it's not extremely level I mean I can pullback my skin when penis was normal and even I can pullback during erection but it might painful sometimes, also I take care of my penis hygiene. Yet my friend doing doctor degree tell me that it might be melanoma (skin cancer of penile) and now i'm so damn scared even my exams are near i'm not able to do focus. Also I don't have any symptoms just kind a irritation after urination, I had few bad penis injury in past due to zip accident also I do masturbation a lot I don't know if these are cause of problem, please tell me what is that.