Well, do you have a saved game from before you go to the palace ?

If you can stand to redo this areas it will be the best strategy IMHO. I would go back to that saved game and go around Eastersand killing wolves, then sell all the loot you got and buy potions. Make sure you can buy a spell to heal, like "Cure" too. It is the alternative to potions. If you can't find it on Rabanastre try walking all the way north to Nalbina city, they have better stuff to sell there.

Other than that, run away from the Mimic Queen, save, go back, hit her some more, flee, save, go back... If she doesn't heal herself it might work.