Is saying “bad habit of stress baking” Grammarly correct

yes and if you're worried about grammar it's grammatically correct

the expression used by the character refers to the difficulties faced while seamen are in their journey: reduced food or lack of it, poor amount of potable water, fears related to weather conditions, such as thunderstoms and the good conditions of the boat as well as the homesickness. he says so because it is not precise the time a journey may take and even if they come back home alive.