Re: You may lose hope in other cryptocurrencies but not in bitcoin.
People didn't believe in bitcoin, so they sold it in 2011, 2014, 2017, and so on.
When you sell your Bitcoin, does it mean you don't believe in Bitcoin? 
People sold their Bitcoin because of many reasons. Some people sold their Bitcoin because they need money urgently, other sold Bitcoin because they want to secure profits and buy again in the next correction, and there are also people who sold some Bitcoin because they want to diversify to another asset.
The future is not a guarantee so it's all in our decision whether you want to take the risk or sell and back to the old centralized banking system for your payments.
There is no matter that has a guarantee for the future, everything is unpredictable. However we can learn from the history of Bitcoin price development. It is very clear that Bitcoin price keeps growing from one cycle to another cycle. This should ensure us that Bitcoin has a big potential for the future.Well, I personally still use banks, here we can't separate from bank system. As long as the law in your country can't legalize Bitcoin or altcoins to be the payment tools, there is no way that we can fully use crypto coins in every aspect in daily life.