anxiety about being able to skimp on sleep

I'm 33 weeks and doubting how I will handle little to no sleep. It's been a while since I've pulled an all nighters in college or even gotten a few hours. I want to be able to nurse or pump every two or three hours to get my supply up, and I know that there's also the tendency to stay up because the baby is crying or whatnot. I installed the BabyFeed app on my phone and programmed eight feeding reminders to give me an idea of what I will have to deal with. I sleep through these reminders. Yeah, I know it's not like there's a baby actually waking me up, but I just don't feel confident that  I have the willpower and discipline to be an attentive mom to a newborn.