There is nothing to do much with China's ban.
It's more manipulative movements where sharks and whales + institutional money drive price artificially down ... why ...
... because of you small fishes. They want you - small holders to sell at lower level.
Amen.

There are only 21M of BTC exist, majority are hold long-term in trezors.
In time, more and more BTC will be out of market so sharks wants to accumulate now cheap way.

By the way, you should diversify your portfolio.
Do not keep everything in BTC. Spread the risk - there are a lot of other great crypto to invest.
World do not end up on Bitcoin only.