Long story short : I messed up my GPT and went on to try to fix it without asking anyone, just searching around. Didn't turn out too well.
Right now all I'm concerned about is a 500GB that I formatted as exFat partition with some important files. But on my journey to fix, I may have used the 'fdisk' command on a GParted Live CD I have (couldn't get on any OS) and switched it to ext2. Now I can't get access to it, doesn't show up on Windows or Mac. Only on the partition table as ext2.
I have got access to most of my files through recovery softwares but they cannot recover with the originial directory or file names, which would be a pain to fix.
I want to know if there is a way to change back the file system to exFat without having to format it.
Thanks in advance.
This is how my partitions look like right.