I dont know shit about plants please help my son Ferdinand the mosaic plant

okay so ive had this plant for a little over a month he WAS covered in leaves and had red veins and everything, kinda like the last 2 pictures but very tiny. ive had 1 plant before this and my cat kept biting the leaves and killing it so i put this one on top of a shelf beside a window in the living room and then i kinda forgot about him for 2 weeks….

by the time i remembered him his leaves were all fully dried up and falling off, i moved him to a shelf in my room where i can see him and he has indirect light + fairly regular watering once a week

2 weeks later he hasn't really recovered much. i never swapped out the soil after i got him home (still haven't but) i did pull him up today bc i realized theres this paper thing around the base in the soil so i took that off, released the roots from the soil in some water and cleaned off a lot of the dead leaves (this is probably unneeded and maybe a bad thing but i literally have 0 experience here and wanted to see what the roots looked like)

the roots are extremely extremely EXTREMELY tiny and fragile which i feel like isnt a good thing bc my other plant has super thick roots.

he's still in a nursery pot with holes on the bottom, and that pot is inside a closed one with those floral rock things in the bottom to hold the nursery pot up (picture 5 + 6) bc i heard someone say something about it helps prevent root rot

i dont measure how much water i give ngl i usually just put enough to where the plant isnt drowning but has moist soil. i also use a plant mister thing whenever i remember to use it at least once a day. i think that theres some new leaves growing but i really dont know anything about what im doing tbh

also picture 3 is the best i have for what he used to look like, he was bought at a grocery store so 💀 but picture 4 is the type of plant he is.

PLEASE help my son bc at this point im starting to think it might take an act from god to save him