Extreme exhaustion with a 21 month old

I am almost 8 weeks pregnant with our second (convinced it's a boy) and I have extreme fatigue. I am an online college student and stay at home mom and have a husband as well to take care of. I'm trying to not drink mountains of caffeine, however, by nap time for my daughter all I want to do is crawl into bed and die which that is my usual homework time period is when she's napping. How do I fight the fatigue that is my number 1 pregnancy symptom right now and I am struggling so hard I'm exhausted non stop. Sos