Is there any way that i can stop masturbating by taking medications? it's been 3 years that i've been masturbating. 2 to 4 times a week.

There are no medications I am aware of that stop a habit you find gives you pleasure. The practice of self sex is not particularly harmful as long as it does not otherwise keep you from pursuing productive activities. Many document its peak frequency in the teen years with a decline in adulthood. If you want to change your life, look into people oriented activities that you would find enjoyable.