Never regret spending your BTC. That's what it was born to do. The purpose of bitcoin's life is to be spent.
Some people tend to "look back" and have regrets, some keep looking forward. Too many don't understand that's unhealthy to look back because you'll always find something you could have done different, better.
This being said, it's clear that selling Bitcoin for NFT turns out to be a bad business more often than not. But OP should take it as a lesson instead of regretting.
I learned the hard way that Hodling BTC is the only way. [~snip~] Just HODL and you would have more more money than anyone yield farming in long run.
Indeed. It's a valuable lesson and you've learned it.
And keep in mind that in the same way all who got burned in the ICO craze warned that NFT is not a good investment and you've ignored that, many of the next ones to come will be burned by the next similar craze, just because some don't believe the warnings and "want" to learn from own experience.