i broke my site, how can i get it back

I took a look at the source, and tried to pull up your css file: https://www.nutritolavita.com/wp-content/themes/desk-mess-mirrored/style.css – what i see there is php. So it seems you have overwritten that file. Since that’s pretty much what controls your theme, youre gonna need to replace that. Hopefully you have a backup? ??