I'm feeling the same way, except that this is my first pregnancy and I didn't have the prior good experience to compare. Before I got pregnant, I was working over 80 hours a week, at a high-stress job, with occasional 30-hour shifts with no sleep. We don't take sick days unless we are dying, and we work through holidays. I boasted about how little sleep I needed. During this pregnancy, I have felt like crap the ENTIRE time. The vomiting only stopped recently (well, it actually still happens once a week, but that's a million times better than it was). And I sleep an INSANE amount (of course I also have difficulty staying asleep for more than several hours now, have constant nightmares, and wake up sore). Thankfully, I scheduled this year so that I would be on a sort of break, working at my own pace. But I feel so incompetent. I'm not nearly as productive as I could be. My husband is understanding and tells me not to worry about it, that my body just needs rest now.
I don't know how I can have a second child if pregnancy is this bad

I won't be able to have another year off like this, and I can't imagine working my regular job feeling like this. I actually have to go back to that job in the last month of pregnancy (mid-June) because that is when my break year ends. Not sure how that is going to work out (sick days aren't acceptable in my field)