semen starts forming in a male after attaining puberty and then is made continuously. since a human being can not store too much of it so it comes out with urine or in night emissions if not used, it is a natural process and nothing to worry for.masturbation is away of passing out semen as is sex,both methods are normal. masturbation doesn t cause any weakness nor does it affect sexual tendency of a male. memory loss,poor concentration,weakness as you posted can occur due to anxiety. you remain preoccupied with guilt of masturbation most of the time, if you treat masturbation and nocturnal emission as normal phenomenon, you will regain your self confidence and all your anxiety will go off.