Factory reset did the trick. FOR NOW...................

Can this be related to back ups? Maybe the phone is making a shit ton of back ups without deleting the old ones?

I will do that later if I can't find a solution. It will, at least, separate my sd card from the main storage.

I'm about to try full reset off and on again.

I'm poor and my phone is 4 months old. I need a fix lol

I tried disk usage but just shows a bunch of green squares and nothing related to system files. The biggest files in diskusage were whatsapp videos of 14mb.

I did a system update recently, might be some kinda of bug. It's either that or related to sd card.

It must be something related to SD card. I just tried some type of SD Card formating because it was full and now my sd card kinda merged with the system storage. When I remove the SD Card it says 128 of 128gb full. But before opening the screen from the print it says 40gb occupied... I've recently updated the system too, might be some bug, but I've seen this problem in many other posts from 3, 4 years ago.