What is this??!

I do my own acrylics and recently i wanted to do a fill-in so i filed down the gel polish and my nails look like this underneath.

i have since removed my acrylics completely to find them extremely fragile (which is mostly normal with acrylics) not only that but they also are separated from my finger down to where the white ends (?)

this has never happened to me before or when i went to salons so what exactly caused it?