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 !!
Yes, you had a good idea, forget about crypto for now, divert your attention in another thing while is not good but if you have more stuff to buy a coin like ETH do it now, as the market fell.