Tired all the time!

I'm 9w5d with our 4th baby and I'm so tired all the time. All I want to do is sleep all day! My husband is military and is on 3 section duty right now so he's gone for 24 hours every 3 days. I can barely function, I have enough energy to feed the kids hen that's it. I feel like such a lazy mom. Anyone else experience this? I've never experienced this with my girls. Help 😢