M&M3 is very much an old-RPG design, and you take chances that can lose or get you a lot in a single moment. The old adage, save just about every turn, really applies, if not nearly as much as in M&M2--which in turn was quite a bit easier than M&M1.
There should be a trainer you can use out there. Check out the web for one. I think you'll be able to give yourself back everything you lost, assuming you don't have an earlier save file.
EDIT: This
editor might do the trick. Haven't used it, but it is from RPG Classics, and their stuff is tested and usually pretty solid.