has this ever happened to you /vr/? I was emulating pic related, reached the end of the flaming level on the first megami tensei, after getting an item that would let you see where the boss of that section is hiding (I think it was Set), but then I stopped playing for a while, when I decided to come back to it turns out I must have accidentally deleted the save file somehow because the file was clean, or perhaps it got corrupted, no idea.
I had a backup on my phone, but my phone happened to met its untimely demise not too long ago, so Im shit out of luck.
Lost them all the time due to faulty third party memory cards, didn't even care most of them were games I had no plan of returning to anyway.
you sure you haven't changed the filename or folder? Emulators don't usually corrupt saves like that
Try looking into your emulator's sram folder if you can still find a file named megami tensei.
You know the thing where nes games said to hold reset before turning off power? One time, I just turned the game off without holding reset, and I lost all my zelda saves.