Tired of Being Tired

I've been having trouble sleeping for weeks now. I'm a SAHM so when my SO has a day off I let him sleep in. Even if I try to lay down I'll end up tossing and turning or just not being able to fall asleep until 5am. Then I get up with our 5 year old between 7 and 8. I'm constantly tired throughout the day. I don't have energy to do anything. I keep up with the housework only after I haven't done anything for a few days. I'm 32 weeks with our second child and I know sleep will be practically non existent when she comes but right now I'm exhausted and she isn't even here yet. It makes me fear for her arrival. I get really bad headaches from not sleeping and then having morning sickness. I don't want to take any medications because I don't want to put any drugs in my body unless its 100% necessary. I had a sinus infection and bronchitis for 2 months that finally went away about a month ago. I also had the same thing in my first trimester. I was on antibiotics for both and took robitussin, cough drops, vics, and mucinex for both. That's why I'm trying to stay away from drugs. It's getting really hard to function. My memory has gone from bad to crap. I don't get dressed most days. I've tried all sorts of relaxing things before bed but none of them have worked. I get snappy and don't like who I am as a person when I'm tired with morning sickness and headache. I don't know what to do anymore. Sorry this is so long. I guess it's more of a rant but advice is always awesome.