This can only show that there is too little experience, lack of understanding of the market, and failure to take profit in time. This is done to avoid turning profits into losses. I have done it before, whenever something like this happens. I will regret it, but it is useless, like a stop loss, once you reach the point you want to sell, you must sell to prevent more losses.
we should really realize that crypto is full of surprises, prices can go up or down unexpectedly. regret is also useless, as you said, it will only damage our mental. it's better to let it go and be more grateful for every profit we get. thus we will enjoy enjoying market price fluctuations more.
Don't push yourself too hard to reach the target so or so, if indeed we need funds then just withdraw if it's profitable. it's useless if we can't enjoy what we're fighting for, right?