Pokemon Quest has a glitch that allows you to run away forever. You need to get your cursor just over the very edge of the run button and the cooldown is negated (mash A). You can use it to run endlessly with your last Pokemon, in order to revive the other two Pokemon in your party. This should make it a lot easier to beat the bosses!
Protip: Add a healer with the Sharing Stone equipped to your Pokemon team and you can now full heal between all fights while using this glitch!
Note: This glitch was performed on an unpatched version of the game. It is likely to eventually get patched.