Due to the unstable exchange rate, bitcoin is risky as a storage method (to store money cash or even gold is more predictable) but bitcoin still works as an accessible, quick, low-fee, international, pseudonymous and safe method to send and receive money (and buy/sell products and services) without banks or government ID. Bank transfers, PayPal, Western Union or cash in mail cant offer what bitcoin offers. If you convert your bitcoin to fiat (=cash) for daily living costs, you will be fine. If you want to speculate/invest/hodl and dont invest more than you are prepared to lose, you will also be fine. Bitcoin isnt dead (and will never die as long as people run full nodes and miners) and still 100% works as a currency.

I remember when bitcoin traded at $250, then $500, 1k, 2k, 5k, 10k and 18k ATH. I understand that it can be dangerous to lose money due to course changes. I exchanged some of my BTC to cash for security and because I cant afford to lose more. If you feel anxious about the drop, do what is best for your situation, if that means hodling or exchanging some of your bitcoin to fiat. But even $4000 isnt bad in the bigger picture and definitely doesnt mean that bitcoin is dead, as a currency or as investment.