36 weeks and completely exhausted

I'd say at this point I'm sleeping 5 or 6 hours at night (taking into account all the times I wake up to go to the bathroom or change positions) and probably a solid 4 hours during the day. Sometimes more during the day depending how well I sleep at night. But even then I'm completely exhausted, and my arms and legs have started to feel like dead weight, completely tingly. And I have absolutely zero energy! My Dr has already told me I have low iron and I'm taking iron supplements in addition to my regular prenatals. Any advice?? I'm just so ready for this baby to be here already!!