I feel for you. You are right, who ever says masturbation is good is dumb !!!. You have heard of phrase "Misery Loves Company".... There are old farts and stupid people here that are addicted and would love nothing better than spoiling another.
To be fair, like anything, over masturbation is very harmful. In the short run, it will not be bad. But the problem with masturbation is ... it is like drinking, smoking ... it is addictive. Since it is very accessible for self, it becomes a habit pretty soon.
For quitting, you need the strength. Strength from understanding the progression and effects. Being aware of these it gives you the resolve to seek a solution. Have patience and read below. I will provide effects of over masturbation and some solutions to overcome the same.
Look no one can help you other than yourself. Think of what masturbation makes you do and what effects it has on you. Once you become used to your hand pressure, the speed and feel ... it is almost impossible to enjoy regular sex. Nothing can be as intensive in the beginning. However, soon this alone is not enough and you need more motivation. As much as you try, body is used to the feeling, and will push you and consume you. In order to get relief, mostly people become daring. Some become exhibitionists, some seek sex on line with strangers and expose themselves to all sort of risk. For sometime however, this is also thrilling. But soon this is not enough. Where do you go from here? To seek relief you will masturbate more and more, but get smaller relief.
Over years of masturbation, the sensitivity to hand decreases. One's penis shrinks both in length and in girth. There have been post after post here with people, some in teens that have erection issues, with ejaculation and inability to experience normal sex after some years of addiction to masturbation.
I am sure no one in their right mind would seek to be in this position.
You are intelligent as asking the right question is half way to the solution. Once again you are your own best friend and can help most.
Whenever you feel the urge to masturbate, don't be alone. No matter what time or the situation is, go to an area where other people are. Try to help with their work. Seek to have conversation. If no one is available - go walking, running, swimming, biking, work out ..... Listen to music. Develop habit of reading and / or an hobby. Go to the library and learn about it as much as possible. This way you become the expert and have something to talk about with others. This will make you feel achieved and help take mind off of masturbation.
Read biographies of some of the people that achieved incredible things even under extremely challenging conditions. I would suggest Gandhi, Lincoln, Franklin and many such. You will see how they overcame incredible odds to achieve. Nothing could stop them. Let their experience be your guide. Let it be light in your dark hours.
You should also think about Yoga, Pranayama and/or meditation (Breathing exercises) All of these are known to calm you down, reduce stress and give you strength to focus. Breathing exercises especially help breathe in and retain oxygen the life giver for all cells. This alone has been shown to take away many of the psychological problems. See brain is like a muscle. You need to control it. Mind is incredibly powerful if you know how to use it. Meditation teaches you how to control the brain and focus on what you want to achieve.
Some say you can start reducing number of times you masturbate over time. This is tough and may not work. I would say, determine that you will not masturbate for a month say. No matter what do not masturbate in that period. Then may be once and again go back to the resolution period where you will not masturbate, no matter what. This way you will develop confidence in yourself.