How to deal with impotency?

hello everyone im 21 male...im facing this problem since 3 years...im really worried cozz after some years i should get married...and im masturbating since several years i worry is that the cause for this problem...and im bit mentally upset since 3 years due to several problems and i have heard that persons who have mental ailments have a possibility of getting impotency kindof problems ...is that true....i am really worried plzzzzzzzzzz someone help me