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 !!
Don't try to quite ETH. It won't keep on declining forever. Remember that, the whole market is red and not ETH alone. It will soon get on it toes and to the moon, we will go again.