Any idea on how to fix my corrupted MH3rd JD save file?

[LunaMoo]

Unfortunately if you don't have backups in any form(or at least in-game savestate) you can say bye bye to your character since the file really is messed up.

If you will ever try to cheat again, check this ~ while I don't really maintain it anymore, those cheats still work fine as I just checked and most of them should also come with some safety measures to avoid problems like the one which killed your character.
Also not sure if you aren't confusing this ~ "Ctrl+T" on windows does not activate cheats, it activates cheat menu which can be entered from pause menu(the one you access by pressing esc in-game) where you can select cheats.

I would recommend to only enable cheats when you want to use them - disabling them later(edit: and well yeah make savedata backup before trying untested cheats;p). Making cheats for psp was always relatively easy and because of that there are many bad cheats flying around the net, for example those simple variable changing cheats in MH games should all include safety checks, cheats you used didn't had any checks at all meaning even if any of them would be correct, your game could get messed up anyway by just leaving the village with it activated.