Sleep

I need sleep... And my fiancé works from 8-6 , while I'm with our two kids, and I don't mind at all, he even let's me sleep in whenever he can let me. This morning before work he got the kids up and ready for the day , to let me sleep.. Yesterday he let me sleep til 12:00 pm.. I'm still exhausted!! I don't know what to do.. I'm falling asleep sitting up ..