Why don't you buy again? There are many chances to buy again before Bitcoin and Ethereum increase again to their new ATH. I think your biggest mistake is missing the chance to buy again. In 2020 or even in early 2021, is a good time to buy. You must be aware that this year is a bullish time. Why you don't prepare your crypto assets?

Anyway, it shouldn't be a big mistake as long as you could take profits from selling them. I also sold my BTC or ETH each year, but I will buy again in the bearish season.