Have in mind Potions heals 20+ 10% hp each turn, for a total of 20+30% hp (during 3 turns), you should be being healed at least around 150 hp in total at that point, you can also use them before battle. I would need to see what you have bought and what stats you have boost. Rebalancing without knowing the exact details and how are you playing it may be kind of hard ^^u
Did you buy Heal? or other Skills?
If you are having issues all I can suggest you for now is gaining one or two levels at the forest until the enemies are auto-defeated. One single level can make a difference. The start of the cave also have battles with low quantity of enemies.
As I said I know some players may find the game too hard, so I'll probably lower the difficulty at the begining so it isn't that hard to learn the mechanics.