Don't ever put all your funds in one investment. Always allocate your funds across a variety of investments.
Bitcoin is still one of the most risky and speculative assets, and will be for many years.
I don't think it will go to zero as there is too much interest and there are buyers.
I would be playing the price levels. Dollar Cost Average down from here. For eg. 20k, 15k, 10k, 5k, 3k, 1k.
No-one can predict a bottom but compared to a year ago you are getting a bargain buying bitcoin now.