Hello! Can anyone help me?

The power flickered for a second and my computer shut down. Ok, it happens. Steam was open in the tray, but the game was not. It's the third time that I turn on my computer and, when clicking on the FFXIV icon, Steam asks me to install/download it all over again. All the files are in the "steamapps" folder, but the launcher and Steam still forces me to download 30 GB+ all over again.

The process takes hours and hours... And just on the only free time I have to play. It's pretty disappointing.

Could anyone tell me what I can do to solve this?! Anything. I really don't know what to do. I've tried several methods, tips, searched on various platforms (on Reddit, the Forums too)... But nothing solved the problem. And I'm not very good at solving problems like these, which makes it very frustrating.

Oh, and if I try to use the "boot" or launcher directly from the folder, when entering my SquareEnix ID and password, the only thing that appears to me is this: "This service account does not have a valid FFXIV license for this plataform." And the launcher only gives me the option to close it.

I bought the game through Steam. Could I install the game or open it in another way?

Thanks in advance for anyone who tries to help me...