Is this pregnancy or something else

I am 25 weeks today and I have been super tired for the duration of this pregnancy. Even before falling pregnant I would sleep a lot.

I can sleep 9 hours at night and when I wake up, I don't feel well rested. I may have woken up 2-3 times during the night like to pee or from something else but I fall right back to sleep. I have no issues being able to fall asleep. I literally lay my head down and I'm out. I have fallen asleep at parties, when my husband has is loud friends over. Through almost anything.

I used to be able to go through an entire day of school and work with 6 hours of sleep and no naps. Nowadays I work 12 hour shifts and I get through the shift but I am exhausted.

On my days off I sleep in until 9 or 10 and I wake up to eat breakfast only to be taking a nap again at 11 or 12.

I have gotten my thyroid checked within the past year and they just did a TSH. They didn't check my T3 and T4. I am not saying it's my thyroid but my Mom had a history of hypothyroidism and had to take synthroid.

When I tell people I'm tired, they say it's because of my pregnancy but I was doing these things pre pregnancy and now with pregnancy it has only gotten worse. I have no motivation to get up and do anything. I wanted to wash my car today but after cooking lunch for my husband, I had to take a 2 hour nap. I feel so defeated. How will I last with a newborn? I don't want my son growing up thinking something is wrong with mommy and she's lazy.

I drink tons of water, and I try to eat right and I even exercised 5x a week before getting pregnant and I got pregnant first try. I also have never miscarried and our baby is perfectly healthy. So I am thinking if it were anything to do with my body I wouldn't have been able to get pregnant and have such a smooth pregnancy.

Can anyone give me any insight on what this could be? Maybe depression? Pure laziness? Hormones? Any input would be appreciated.