Welcome to the world of bitcoin mate, where uncertainty is the surest thing to happen in you.
Going back to the question, I would say that it is very possible that bitcoin will reach zero. Even its creator have said already that in 20 years, bitcoin will either reach a billion or zero.
For now, what we do is to make it possible to have other investments not just in bitcoin.
In the morning I read the news where one of the leading multinational finance company stats that the Bitcoin & Other Cryptocurrency will be zero. So is it possible? If possible then which instructions should be followed getting out of debt?
It is possible because everything changes in this world. It has an unstable price that's why it is possible. Bitcoin is limited of supply and it will be zero if no one it left.