Firstly know that masturbation is as not dangerous.
Neither is it harmless.
To masturbate once in a while is sort of ok, i.e. no problem
there. But to indulge in it daily is not good. It may do no harm to
your body, but it does damage your personality. You
will harbour this secret of yours and it will affect
your relationship with others. Your sexuality will also be
oriented to masturbation, that may not be a problem if that is your
preference.
Masturbation is a physical cum mental activity, and
if done regularly will, in the long, run affect
your thinking process. You will not go mad, but people
will notice that you are kinda "funny". So masturbation is
not altogether harmless.
Do not try to stop masturbating outright, but rather say to
yourself that you would masturbate later, tomorrow or at the
weekend. Then every weekend only, and slowly you would not indulge
in it daily, but only once in a while.
Also look at the opportunity to masturbate, you will most likely
masturbate when you are in the setting ideal for masturbating. Try
to change the setting like having your sister to share the room
with you, or leave your door open when you are in your room.
exactly what this guys says...