Cooked food. All cooked food has a wellness rating (even though it isn't listed). Even baked potato will raise your wellness slowly (something like 0.2 each, I don't really know the rate). Just keep eating good cooked food and it will slowly rise... I know it is rough trying to get above the base (50) because dieing is so easy to do early game in Darkness Falls, but eating good food is how you raise wellness (max health/stamina).