I'm not very knowledgable tech-wise, so I hope it's not too pricey to repair !

HDD are not expansive but that's where everything is saved

Yes, replacing the hard drive is expensive, but not by much, so it won't be a problem
I've reinstalled windows at the moment and will probably be able to continue working tomorrow

Only if you have no backups or it's soldered to board. (LOL@non-slotted SSDs on laptops)

Glad to see you got it going. At least for the most critical files, a USB (or SD) Flash drive is a nice almost entirely crash-proof way to keep a second copy. Was gonna say drop-proof, but there's a different kind of dropping problem with fingernail-sized drives. ;) I guess in theory, you could 'crash' the USB drive by dropping a laptop in a way that it breaks the pins.

Old joke about everyone keeps backups - the second time. It's a horribly painful lesson. :(

Yes, that's why I try to periodically store all important information on a USB drive

Third time: You learn to keep them automated and not in the same room. Ugh, my nightmare scenario.

Oh no!! That always sucks. I hope you didn't lose anything

Lost some art I drew, but nothing critical, everything is still on the flash drive, so I should be able to continue soon. Today I'm installing Windows and software, so I'll be able to continue working tomorrow

That's good to hear at least..

Thank you