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It seems from your description that what you have is PEARLY PENILE PAPULES(PPP) ,which is very benign condition and absolutely normal to have.
It is nothing but very tiny sebaceous glands (oil glands) over the sulcus.You should just try to keep the area clean with soap and water.
It has nothing to do with masturbation
As far as skin retraction is concerned ,again I would say that it is normal what you have.
Hope this answers your query ,if you have any further questions kindly write back to us.