I am 25 years old, unmarried male. I never meet in a physical relation with any girl, but I am masturbating 5 or 6 times a week because I enjoy it a lot, and if I don't do it, my penis is always in crazy mood. I constantly have sexual feelings if I don't do it and there are bad thoughts around in my mind. That's why I masturbate too much perhaps, but I don't know of any other way for me to handle these feelings. So, is masturbating bad for your health or not? How do I solve the matter? It's not possible for me to marry now.
When you are a young man, it is very easy to establish habits which are hard to change. That is why marketing people target young people for their wares so often. They know that if they can get a young person to use their products when they are young, they will continue using them for the rest of their lives.
Another problem is that some products are designed to leave you wanting more. For example, most soft drinks contain caffeine and salt. The caffeine makes you urinate more often and the salt causes you to become thirsty sooner. Thus you drink a soft drink to quench your thirst, and it does for a while, but you end up wanting more because you become thirsty again. So you reach for another soft drink, and a repeating cycle is established.
I don't know if you are using pornography to trigger your masturbations or not, but I wonder since you mention bad thoughts if that might be the case. Pornography is a product that is sold to young men and it is one that easily traps them. Your own body is used against you. The release of semen gives intense pleasure and your body is constantly producing more semen. Yet, what young men don't realize is that pornography isn't necessary, but they have formed a habit of using it. Worse, it fills your mind with perverted ideas about sex, so as your seminal vesicles fill back up, your mind turns back to the garbage that it saw before. There is an urge to look at pornography again, and thus an endless cycle is set up.
Worse, while masturbation does give temporary relief from the sexual desires of your body, it is not fully satisfying -- not like sexual intercourse with your future wife will be. Thus it leaves you wanting more soon after, becoming a part of the cycle.
Masturbation by itself is not harmful. There is a detailed discussion of what can be misused to become harmful in "I'm still confused about masturbation. Is it right or wrong? What are your thoughts about it?" If you want to regain control over yourself so that it doesn't feel like masturbation is controlling your life, see: "How do I break this habit of masturbating?"