The struggle is real

My son is almost a month old. Before going to bed, i change his diaper and feed him and get maybe an hour and a half of sleep before he wakes up to feed again. Well when he wakes up I end up giving him a boob and while he's nursing I always fall asleep. No matter how hard I try to stay awake I fall asleep. I don't stay asleep for too long, I wake up maybe 10 minutes later, change his diaper because he likes to poop while eating and give him my other boob. Well I fall asleep again and usually sleep for like an hour 1/2 sitting up holding him then I wake up and if I try to put him in his rock and play he wakes up and wants to nurse again. This repeats all night long 😩 so I spend 95% of the night sitting up with him in my arms and not really getting any good sleep and my butt ends up hurting so bad from so much sitting 😩😩it's my fault that I fall asleep but I don't know what to do to keep myself awake