Dr i am 21 and have diabetes. ... i masturbate daily. .. is there any harm and will i suffer from impotency and what should i do ?

Control sugar: Your recreational activities will not cause it to "wear out" and lead to impotence. What will is the neurotoxicity from poorly managed diabetes. Check your sugar regularly and keep it in the target ranges to minimize neuropathy risks as you age.

Not necessarily: Masturbation does not cause impotency. Diabetes complications can lead to erectile dysfunction however if your diabetes is not well controlled.