Edited prose falling flat? Check your inner critic

Ernest Hemingway said, "Write drunk, edit sober." The problem with editing sober, though, is if it goes too far unchecked, it can turn into "church lady" sober. The inner critic taunts your loopy, messy prose, making you feel stupid for writing it in the first place. Sort of like this:



The unfortunate result of this, at least for me, is prose with all the life sucked out of it, leading to flat characters and a weak plot. Yeah, the sentences go together, but if there's no life in them, they're not worth reading.
I ran into this with a recent short story I wrote for my MFA class. It explored what might happen if our bad ideas didn't come from us, but from external, invisible beings who planted them to ensure we learned from our mistakes. (Much like an inner critic, no?) My protagonist is one of these invisible beings, and the seed she plants backfires. Forced to confront her lizard boss Roebuck, she finds out the whole system is rigged. 
Here's the scene as I turned it in for class:

I can’t move. Can’t think. I stare, feeling like I’m seeing Roebuck for the first time. “Why control us this way? Make us do this if it doesn’t help the humans?”   

He flicks his tongue. Irritated. “Ignorance keeps the system healthy. Don’t question it.”

This isn’t right. My entire being buzzes with a new clarity. One that allows me, for the first time, to see into his brain. His memories.

There’s a silver medical table, with his former lizard self, much smaller, and squealing in pain. A human in a white lab coat injects him with a red fluid.

My mouth gapes, and I can’t speak. Zorg was right about pawns. I wonder how much he knows. How much he wanted to tell me, but was afraid of what Roebuck would do if he did.

I narrow my black eyes. “You don’t do this to help the humans. You do it because you want revenge on them.”

He growls, and pulls me toward another wall. An invisible door, one I didn’t know was there, opens. “They need to know the harm they cause others. Be accountable for it.”

The room seems to elongate. I stare at the empty elevator pod at the other side of the room, starting its countdown to leave.

I can’t let it. 

Here's the same scene with some deleted lines added back in, more showing instead of telling, and some sentences combined:

My joints stiffen. I can’t move. Can’t think. “Why control us? Make us do this if it doesn’t help the humans?”   

He flicks his tongue, irritated. “Because it works. Ignorance keeps the system healthy.”

I stare at his hooked face with its sinister scales and needle-sharp teeth. And for the first time, I don’t trust it. Fueled by anger, my mind buzzes, allowing me access into the deepest part of his brain, where his memories live.

On a silver medical table, his former lizard self, much smaller, squeals in pain. A human in a white lab coat injects him with a red fluid.

So that’s why. He doesn’t want to help the humans. He wants revenge on them.

Zorg was right about pawns. I wonder how much he wanted to tell me, but couldn’t, afraid of what Roebuck might do.

I narrow my black eyes, scathing. “You’re using us. All of us. To hurt them.”

"I don't have time for this." He growls, and pulls me toward another wall. An invisible door, one I didn’t know was there, opens. “They need to know the harm they cause others, and be accountable for it. Someday, you'll understand.”

The room elongates, and I stare at the empty elevator pod at the other side, starting its countdown to make someone else’s life unnecessarily miserable.

I can’t let it. 

  The scene still needs work, but at least I've gotten hold of the emotional heft needed to carry it forward. I took a overly telling sentence that involved "seeing Roebuck for the first time" and showed how she perceives him differently instead. I also inserted more of Roebuck's reactions to her. But most importantly, I allowed my sentences to be a bit messier, inserting more cadence and variety within the prose by default.
So what about you? What kills your prose, and what have you done to spruce it back up again?