Dear, Welcome to HCM We understand your concerns I went through your details. Night fall is nocturnal emission (NE). this is a natural process with which the sperm stored within your body is released once you do not masturbate or engage in sex. To clear this, practice masturbation or sex thrice or four times a week. Premature ejaculation can be physical or psychological. As you said it is from your adolescent period, I suggest you to consult an urologist for investigation. You could need treatment. Watching porn clips, masturbation etc are not unhealthy processes. You should watch they should not become habits. Depression is a neuro chemical disorder and is usually treated with drugs, psychotherapy and relaxation therapy. Consult a psychologist. If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute detail possible. Hope this answers your query. Further clarifications are welcome. Good luck. Take care.