Retroactive taxation on cryptos?

I've always been the type of person who buys cryptos (mostly BTC) and leaves them for years. Then I sold them for a profit. Rinse and repeat. But this cycle is different in the sense that I sold it six months ago and now for the first time the news came with “EU now wants to introduce crypto tax”. It was clear to me that the state would want to get involved sooner or later; every new source of money would have to be exploited by politicians. My question would be: if I now before this re