What Causes Spot On Penis?

from the age of 15 i am mastrubution three times in a week and it still continu for the age of 32, now i am 32 , there is some spot on my top of the pensi and when i am seeing any hot seen i cannot control my sex and immideatly i mastrubat. now my faimly wants to marry me but i am so afraid to marry , is there any test to known that i am ok and i can marry and give good sex to my wife and become a father.