Nightfall is the uncontrolled ejaculation of semen during sleep. This is generally caused by sexual arousal and orgasm from dreams. Night fall or nocturnal emission is completely normal for males during teenage and early adult years.
Excessive masturbation may have been the cause of your problems to begin with. Reducing your frequency of sex and masturbation from now on will help to prevent early ejaculation and seminal leakages from reoccurring.