I think that anything terrible has not occurred. Even those who sold their bitcoins at the price of $ 1,900 bought them cheaper and still earned it. Yes, of course they could make more money if I had patience, but then the next time they will be more patient and it will allow them to avoid mistakes in the future.
Learn by the mistakes. That is the for buying and selling.
We tend to somehow panic and make decisions that are wrong. Lucky are those who panicked and still in the right direction.
Selling all nowadays will just be a regret. I regret all the bitcoins I have earned that I sold which makes me comkit more into taking it back. By buying and then making a profit out of it by price fluctuations.