Here I wrote it in the way how I understood it. Is that close to what you had in mind?

Nothing worked for Liam that day. He was as if looking at life from inside a mirror, even at the murder that invaded his mind.
There was no greater desire in the world than his desire to succeed as a painter. Preoccupied, he spent days researching nightmares, rushing in his inflamed mind through color schemes and degradation of color to express them. It seemed easy, but every time he attempted to grip in his imagination, it was slipping away.
Liam sat at the lecture in Art class, but his mind wandered. "Nightmares look like dreams and seem a reality. It’s a mixture of images and sensations in a chaotic environment reigning by fear." These thoughts absorbed him so much, that he was oblivious to the explanations of the professor.
"Liam, pay attention, listen and then apply."
"Excuse me, Master... Are you talking to me?"
"Didn't you hear what I said?"
"No"...
"How could you learn painting techniques if you don't pay attention?"
"It’s not that I didn’t pay attention. I just followed your last suggestion on how to “scream” at the canvas, so that the viewer could hear every brushstroke."
"But how are you going to transfer emotions to the canvas, if you yourself don't get excited about what you're doing?"
Liam cast a foggy look at his master, the kind of look when eyes seem focused but without any light of understanding.
"I am grappling with the look that is not of this world. I see it with the eyes of my mind. A woman peers at me and her eyes cry out for help. That has motivated and frightened me... because, what emotion, apart from fear, will scream from the canvas?"
"Did you catch a dark muse or did she hang you on her hook?"
"What do you mean?"
"Did you dream the image you're trying to revive on the canvas or is it the fruit of your imagination?"
"I dreamt it, but more than a dream, it seems like a nightmare because I move in an atmosphere of fear. I see a beautiful woman, who seems to have been murdered, looks alive and looks dead. She lies on a surface that I can't distinguish well. I feel that she is asking for help, but I don't know what to do. I want to leave the dream but it doesn't let me out. So I have to fight to get back, I feel that it comes for me, but it doesn't have a definitive form. I only remember a transfixed look and a lot of blood running like a dark vine."
"Do you always feel afraid or you are experiencing this feeling only in your dream?"
"In the dream, but I'm obsessed with it. How do I paint something that I fear but that fear belongs to another reality? How do I begin the sketch what I have never really seen, but that comes out in a dark dream and scares because of the uncertainty that surrounds it, but that attracts because one feels part of the history that is woven in that underworld where only a beautifully twisted vision is shown by my mind."