a few days ago ethereum experienced a drastic decline. and it turns out it's currently under $ 200! My personal predictions are wrong, and may not be true. what's the next step?

I think vacationing is a good idea while enjoying a vacation !!
That's for sure. It's impossible to calmly look at such a market situation and how prices are falling. If there is such an opportunity, then it is better to be surely distracted from this horror.