Bitcoin always have a future and certainly have a future. You should not be too nervous! The important is that maybe you have to need so much money to invest in it.
Bitcoin is future digital currency So it will use the most of the people for future transaction process. But it will not affect the other currency. Bitcoin is private process. So it will not affect any one's. It will easyway to save and invest. If you will know the process. you will easy to work and process the bitcoin in the future.
To make it clear, bitcoin is using a decentralized system which is very opposite to a digital currency that has it's own central server to run a transaction.
Bitcoin is the best because it has limited supply and once you invest and the demand will grow you will be profitable.
In my opinion, there is no currency is the best, because every currency has some problems and issues can not solve. Bitcoin is cryptocurrency, but with its nature, it is easy to take advantage its system for crime transaction. The police never know the source of transactions through cryptocurrency (included Bitcoin)