I have sold my BTC earlier @$31k-$35k range long ago. I have invested in altcoin then and made some great profits although I had to lose 50% at the end. Now, I own almost no cryptocurrency other than USDT and a few trash coins.
Yesterday, I was scrolling newsfeed on twitter and got someone tweeted like this, "No BTC holding is risky.' This is somewhat true when I thought it deeply. Now, I got the same feeling. It’s risky to not own any bitcoin. Fiat is getting devalued all the time.
What that person said is very true, there is no risk of holding bitcoins, actually everyone wants bitcoins to be bought and sold when the price is good and high, I think you are too worried about what you are holding, so made this decision to let go of bitcoins at the right time. which is not correct.
The decision to take altcoins in investing is actually not wrong, it's better if you also invest with bitcoin, but you waste a good opportunity to sell bitcoin in conditions that are not profitable for you. Hopefully this will be an important lesson for you in the future.