I am suffering from the problem of nightfall since 2 yrs. How can I cure it at home.?

Nightfall. Please further define what you mean by nightfall so we can help you further.
Nocturnal emissions. This is normal, natural and healthy. If you don't ejaculate often while awake with a partner or by yourself, you'll have "wet dreams." there are medical charlatans and "spiritual" goofballs who will offer to "cure" you. Ignore them. Having sexual thoughts doesn't make you dirty; it's how you treat other people. Talk with somebody sensible -- maybe even dad -- and your own doctor.