How do I know if I am masturbating too much?

Several clues. Frequency of masturbation varies a lot. For some, once every 8 wks seems too much; but for others, once every 8 hrs seems not enough. One should maybe cut back if he or she often thinks of doing it less, if he or she starts feeling guilty about it, if it interferes with his or her daily activities such as school or work, or if there are signs such as painful urination or bloody semen (see a dr.!).