hi..thanks for writing..
masturbation is not a bad habit..it is a way of satisfying your sexual needs in the absence of partner..it does not cause any sexual or physical weakness.
the penis size has nothing to do with sexual weakness and masturbation.
in our culture and community there are myths about masturbation, sex, night fall and sexual problems, these all are rubbish do not listen to them and do not believe in that..
you have weakness, decrease concentration in studies and work because you believe in those beliefs [particularly about masturbation], once you start removing these thoughts from your mind you will be alright..
you shud continue masturbating but not excessively ..you shud masturbate at a frequency of 2 to 3 times in a week. and those who are masturbating are not bad persons, more than 90% of boys in high school and colleges masturbate..if you are not masturbating then it is a problem,understand it,..
masturbation wont affect your marriage life..dont worry..
i hope this will be helpful..best of luck..