I messed up super bad. I'll try to explain more or less what happened:
- installed Windows in dual boot with Ubuntu 16.04 (yes, first mistake)
- tried to reinstall grub using a LiveUSB and mounting/umounting partitions, had EFI errors and such. At some point I stopped seeing some partitions with
- downloaded and used repair-boot-disk, stopped seeing anything else except the LiveUSB with
fdisk -l. The fstab file doesn't contain any of my partition anymore
- tried to mount data partition, had some message "wrong fs type, bad option, bad superblock", out of stress and impatience I tried the first command found after a research... "mkfs.ext4" on this partition. Oops.
- downloaded and used TestDisk, but it only sees a "loop0" partition (around 500MB) and the LiveUSB, nothing from the actual HDD. Same for PhotoRec...
- I can still see the partitions in
- from Windows (still working), I managed to recover 8GB of data from the partition I used mkfs.ext4 on, but it's only some "$BlockBitmap.xxxx.bin", "$INodeBitmap.xxxx.bin", "$INodeTable.xxxx.bin", "$SuperBlock.xxxx.bin", etc. files.
Is there any way to fix this mess? Even partially?