Does Excessive Masturbation Weaken Penis Muscles/

Hi Frnds,
I have been mastrubating since 9 years once in a day. Im 26 years old now.I m going to get marry in another one year.I heard that ppl who do mastrubation will not be able to satisfy their wife and also the nerves around the pennis will get week.. Im very much scared of this problem.Now a days( for past 1 month) im feeling like my pennis is not getting stiff and it is very soft..even one month ago it was very stiff..Im a software professional.I stopped mastrubating for 1 week.is it really a problem or my over thinking is making to deviate like this.Im always thinking like whether i can satisfy my wife or not.. i had very good sexual feelings.Pls help me out.