So done with work. Need advice.

Been at my job for 6 years. The stress and frustration has gotten worse over the years and is definitely not the way it was when I started. Used to love going to work and now i dread it and come home so stressed out. Wanting to quit and look for another job or transfer to another site but afraid no one will hire me because I'm so far along or they won't transfer me because id start the new position right before the baby comes. I don't know what to do but I can't just quit and try after the baby comes. Need the insurance. Anyone have advice?