This ended up working!! Thank you all for the support when I felt like I'd completely screwed the pooch. <3
EDIT: IDK how to close threads or if there's some kind of netiquette around this kind of thread resolved thing
SO...
I recently updated my fw from 6.2 to 7.0.1 using choidejour but I think I did a boo boo. Instead of selecting the exFAT option, I picked the normal one. I'm not sure if this is the core issue but it's the only thing I can think of. Here's a picture because my English is not so good so...