Hello Doctor!
I have a small penis – 5 inches, but I’ve seen my fathers and brothers and they are pretty big so I thought “what a shitty genetics I have!”. But now I think that since I used to masturbate constantly since 7 it may be so because of it. Can it be so?

ANSWER
You are average, not small. And yes, it is possible.
The chronic over-masturbation burdened your hypothalamus-pituitary-adrenal-testicular axis and burned your nervous control. This produced an increase in your prolactin, norepinephrine, epinephrine, and cortisol levels, and depleted the levels of your HGH and androgen hormones, oxytocin, prolactin E1 E3 and Nitric Oxide, which are directly responsible for the growth of your penis. Experiencing lowered levels during crucial years of development may lead to structural alterations.