I recently logged into Hearthstone after a long break. I used to play many years ago, back when Freeze Mage was popular. Over the years, I’ve logged in a few times, but now I’ve noticed that many of my cosmetics—such as hero skins, card backs, and my golden hero progress—are missing. I had golden heroes with over 500 wins, but now my progress seems to have been reset.
Did you log into the correct region? There is a globe symbol next to the blue play button. There you can change the region you are login into.
If you log into a new region then this is basically like starting a new game.