4 times daily continuously for 5 years...!!??? I'm not surprised that your penis has become unresponsive or dead...i'm surprised to know if you are a human..or some extraterresestrial extranatural being or a machine...!!!
Dear Rockstar,
Excessive masturbation of 4 or more times in a day, daily is physiologically almost impossible...after repeated masturbation acts our testosterone level get burnt out...we simply don't feel the urge anymore and naturally,we don't tend to get the erection...Nature has its own way of limitations...this is what is happening with you...but this effect is short-term..you will soon regain your sexual urge and the proper erection after you stop masturbation for a few weeks....!!!
But Yes,masturbation is a healthy sexual habit but when it exceeds 3/4 times a week and that too regular...or when it becomes an obsessive compulsive act as you have mentioned,then there are lots of dangerous side effects...apart from sexual side effects like impotence,loss of libido,premature ejaculation etc..it will harm your Physical,Mental,and Psychological Health....it will lead to anxiety,depression,concentration problems among others...
So please try to restrict yourself..and next time please dont exagerrate.
Good Luck...!!!