Seems to me, you have several hours, while dd is at school and the dh is sleeping, that you could use to exercise, meal plan and so on.
I do understand, that off shift work schedules are tough. At one time my dh worked for an emergency service, was on call. I worked a graveyard shift, and our high school age boys, were involved in everything.
We made it work. Work schedules, parent conference, games, healthy eating, exercise, and a farm.
Go old school, get out a piece of paper and a pencil, and write down, what you are doing now.
Then take a look at that, and figure out, how to make it work! It can. It might not be easy, but the answers are there! It's up to you to find them!

The only person that can help you, is YOU! You have the answers to you own questions, if you really want them.
