File corrupted and I cant get it to work, help!

Hi, so I was working on a (silly but important) music sheet on MuseScore for the past few months, and after saving my work, my computer ran out of battery and shut down. When I managed to turn it back on and open the file, it says it's corrupted. I can't even open it anymore.

I read i needed to installe the Repair Assistant plugin but I tried multiple times and can get open it to install. This project is really important to me and I would appreciate any advice you could give me.