I dont know why but iam scared of bitcoin getting ban.
Because of the china situation is there any possibility that bitcoin will get ban in every single country
No, it is not possible for every single country to ban Bitcoin.
Theoretically it is possible. And it is practical as well. The United Nations can announce that Bitcoins are linked to the sale of online child pornography. Not even the legendary members of this forum will have the courage to defend Bitcoin in such a situation.