My own opinion to this I will say this is not unusual for cryptocurrency. The price goes up and down for pass history Bitcoin price fall and raise dropping at 50% . However It's important to know that the long term outlook for Bitcoin is still positive, with many prediction it will continue to increase in Time.
The past history, you are talking about last year because bitcoin all time high from exchange was around $58k and now we are down to $37k where it is currently trading on exchanges but there is more you need to know. Bitcoin price was not listed on exchange at $58k, it was around some scent to a bitcoin I understand, now imagine you have like $50 dollar worth bitcoin since that year and hold it to now. What you should even be comparing is what $50 dollar can buy 10 years ago and what it can buy now, but if you have bought that amount of bitcoin 10 years ago, you will worth a millionaire, you didn't just beat inflation, you beat poverty as well.
When you want to invest in Bitcoin, what you should be looking after is the long term return and not this short term loss, the loss is not even a loss yet until you sold, the negative 50% you are complaining is unrealize loss because if you didn't sell your bitcoin, you have not actually loss. It's not like I'm giving you assurance of tomorrow but one day, we will discuss how $37k was so high for people, that was how I believe $20k of the previous all time was discuss that it will never pass that price but look at it today.
Keep it in mind that bitcoin has a rule, what goes down must surely comes up and when it comes up, it will make another journey and may return again before sailing off again for another all time high, that is what bitcoin price has been doing historically. So buy the amount you think you can hold and enjoy the ride in profits.