Can't sleep

I work full time and work 5am-130pm Monday thru Friday, by the time I get home I'm so tired I have to nap. Problem is this napping is causing me to not be able to sleep at night. It is now after 11pm and I'm wide awake. I'm only 6 weeks along and I don't want to sleep on my back, I want to try to stop doing that for now. Any advice from the community would be nice.