Someone help me

I need sleep. Badly.
I need my son to sleep. Desperately.

I've really hit a wall the last few days and it's feeling insurmountable at the moment. Mother{parent}hood is one part ecstasy, one part exhaustion. I know this. I get it. But I can't keep functioning like this. I haven't slept for more than two hours at a time (max 3 or 4 on a couple of very rare occasions) in well over a year now. A year! It has to stop.
Before you offer your generous words of wisdom, let me fill you in on the situation:
I chose to co-sleep with my son. He's been in my bed since the day he was born. Initially, I believe, this really saved me  in the exhaustion department. Every time he cried, he was right there to be nursed and lulled back to sleep. Drake and I became such side-nursing pros that I was often able to fall back asleep as soon as he was latched. But then he got bigger. And he started moving around more (read: kicking me in the face). And then his sleep schedule went wonky. Now, not only was he waking up to nurse every couple of hours but he was full on waking up. Wanting to move around and play and explore. That was a couple months ago. It took about two weeks of that for Justin and I to decide it was time to start putting him to sleep in his own bed. We had been introducing him to his bed for months already, as he napped there twice a day, so it wasn't very hard to get him to go to sleep there at night time, too. He cried at first, often for just a couple minutes but sometimes for as much as fifteen minutes - of which I hated every second - but then he got used to it. Now he goes down without a whimper. Binkie. Lovey. Blankie. Done.
But he does not stay asleep. My son still wakes up every hour and a half to two hours. Every night. Without fail. I had really hoped that once he was away from me - away from the smell of me - he wouldn't want to nurse as often. I did not get so lucky.
Do you remember when I told you that Drake has a thing called Anal Stenosis? It means his little bottom is too small. We had to cut out solid foods entirely for a while in order to keep his stools soft enough to pass. We've been able to reintroduce some now, but we have to be very careful about how much and what kinds. He still relies almost solely on breast milk. Which means he still gets hungry every couple of hours. I try to feed him his one solid food meal later in the evening so his tummy will be full at night, but it hasn't made a difference.
I really don't know what to do.
I woke up the other morning thinking, "Something has to change. Tonight I'm just going to let him cry it out every other time." Somehow, in that moment right after a hard night, that seemed like the obvious answer. During the day, he often naps for two to three hours. So he's not going to starve to death in three hours. So I will just force him to go that long between getting up to feed him/bring him back to bed with me. I've now tried that twice and CAN NOT do it. His cries are so devastated after a couple minutes of my ignoring him that it literally pains me not to go to him. And I feel for him! It's like he can understand when I lay him down in his bed that, ok, Mommy wants me to go to sleep. But then once he has been asleep, no matter what the length of time, now it's time for Mommy to come get me. I can hear the, "Why don't you come get me??!!" in his wails and it kills me.
So now what? Is this a case of, "Buck up, girl. That's what Mommy hood means."? Or is there something more I can do? Because, really and truly, I'm dying over here.
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*Please know that I am genuinely interested in any help or advice that anyone has to offer. What I am not interested in is any judgement or criticism of choices my family has already made. If that is what you are tempted to write when you read about my family's choice to co-sleep -or anything else - please, please refrain. I'm only going to delete it.