I have learned something so important in the previous bull market that got to about $30k . When the price of bitcoin was $21k I bought some bitcoin and after getting this amount of bitcoin I had target if it gets to $30,000 I will take profit, luckily it got to the price I was targeting but I was reluctant to take profit like I planned thinking the market price will go beyond $30,000 to get more profits but unfortunately the price didn't continue to increase, but I'm not worried about that because I know the price will definitely increase again and I will get my profit of target.
I am agree with you that btc price will increase once again but we don't know how much time it will take to reach again 30k. It is good to set goals from the beginning that how much profit will be good for you. Actually it was your sixth sense telling you that in this place you should take profit and wait for dip to make another entry But you fell into temptation and lost opportunity to sell at 30k.
If you were a trader, you would know that I can't do much more than that but you just trusted on holding. I will recommend everyone to learn some trading also to get more Profit in these up and down situation. if you have good fund then 50% should be used for holding using DCA while other for trading.