L.A.
You need to ask your friends and family for help.
Who takes care of your child while you are working? See if they can keep your child for 3 hours once a week one day, so you can go home and catch a nap before you pick up your child.
Ask a family member to watch your child for a few hours on your day off.
When your husband can watch your child, Ask a friend or family member if you can go to their house for a nap.
You are going to be so sleep deprived and exhausted once your child is born.. It is just not healthy for you. There is no secret, except actual rest.