Ouch.

Well, I'm guessing you've trained up your weapons quite well, but not your magic.

To defeat the game with minimum amount of effort/training, I suppose train up Cure, Blink, and Berserk, beef yourself up with the latter two before using physical attacks, and Cure as necessary.

You kept Masamune and the Yoichi bow at least, right? You can use them to cast Haste 11 and Berserk 3, respectively.

Also, what version of FFII are you playing?