I love my 15 years old niece very much.But now we are apart bcoz her mom and dad realized our love and vanished me out from their place.She even loves me.It become two months but
Still I am in deep sorrow.Every thing reminds of her. And I am unable to carry on my daily activities.whole day and night I am thinking of her my whole body is desparating.now I am too weak near to death.so *** show me the way.

Are you blood related? How old are you?

Where do you live?
See a doctor if you aren't eating, and a therapist. You need to get away; take a cruise to nowhere.
Marriage is probably illegal where you live, as is sex with someone her age, and her parents aren't going to allow it anyway. You could try to tell yourself that you can wait for her to be an adult.

No one is saying that forbidden love is easy. You either live, which feels impossible right now, or die, and dying isn't easy either. I would opt for a waiting plan for 3 years just to take away a bit of pain.

I love my 15 years old niece very much.But now we are apart bcoz her mom and dad realized our love and vanished me out from their place.She even loves me.It become two months but
still i am in deep sorrow.Every thing reminds of her. and i am unable to carry on my daily activities.whole day and night i am thinking of her my whole body is desparating.now i am too weak near to death.so *** show me the way.

Are we talking incest here? This 15 year old niece is how much younger that you? Are you the brother of her mother, or father?

15 year olds are not legally capable of understanding 'love', 'being in love', or having sex with someone who is a legally aged adult. A 15 year old is a child, regardless of her being your niece.

More detail would be welcome. It seems that the consequences of your actions have not stopped these strong feelings you have toward this child, and you are quite distraught.

To be able to provide appropriate answers to you and this situation you are in, more information would be very helpful.