Well, now you know the importance of multiple saves.
Jokes aside, I'm not even sure if it can be edited in a save as all the variables and switches are in Japanese (my reading and translating is that of a slug), so I'll check it out. As for your level and stats, those are really easy to re-earn and generally manage, so that you don't need to worry about. Could you please tell me how many fog bosses have you defeated so far? This game has a high replay value, and one option is to get one of the end-game endings and start a new cycle. (Ending A,C,D,E. / F & G require a start of a new cycle, but don't continue the game normally.) The other one is to post your save file and I'll try to edit it. If that fails (probably will), I have another idea that WILL work, but again I'll need your save file.