10 fps 100% CPU usage

When I bought the game, I played it without any problems so it's not my PC's fault, I have a good PC. Now, for a few days the game has been running with 100% CPU and 0% GPU in 10-15fps as if I didn't have a  graphic card. The lag starts as soon as I open the game in the menu. It's a shame that a company of your level doesn't solve the problem even after so many days. The game is unplayable. I saw that there are a lot of people who have the same problem. Is there really nothing to do ? We pay for this game, we put in a lot of money on top of it, but we can't even play. Solve it somehow