It's very difficult to buy back after selling. If you sell now, you'll see the price rise slightly in a few days. When you decide to buy, the price will start to fall again, and as a result, you'll be the one losing money.
If you're considering selling now, I recommend not monitoring the price of Bitcoin for too long. You'll find that it rises after you sell, and you won't make a profit.
You can buy it back again in a few months, or even a year or two, and you could make a substantial profit doing so

Selling now and then buying back during the bear market is the best practice for those who are into long-term investments. If you had previously bought during the bear market, when Bitcoin was round $30k or something, and you are selling now, you have already made more than 3x with your investment, take your profit, keep it safe, and wait for the bear market so that you can buy at a lower price again, and then wait for the next bull run again, and then sell again. That's how long-term investors make their money, they don't sell, and then buy quickly after that.
Short-term traders are the ones who can have problems doing this, because if you are a short-term trader, even if you are selling in profit, you will still be hesitant thinking that if you sell, and the price goes up more, you won't have anything then, and you can't buy at a higher price because that wouldn't make sense as the market will most probably start dumping after that.