Welcome to HCM.
Night fall (Nocturnal emmision) is a normal phenomena which occurs when there is excess of semen in the testes.Masturbation
does not have any ill effect on health.
Since you have stopped masturbation, it is quite natural that nocturnal emission
will occur. Do not consider it abnormal. It is the Nature's way of releasing excess of semen.
Don't worry. Nothing is wrong with you.