Please tell me what you think!!! I'd really love anyone's opinions on my work; I'm only 14 and hoping to one day become a professional writer!

Here's the synopsis:
BEFORE:
The hospital smelled strongly of anesthetic.
I always hated it here, no matter how many times I visited as a child: the pale white walls and the feeling of sadness that was a constant presence drifting through the air, the glossy linoleum floors and fluorescent lights that were always too bright, the cold air and the uncomfortable chairs in the lobby.
I sat in one of those uncomfortable chairs nearly two years ago, staring blankly at my feet, trying not to think. I forced every thought out of my mind, put up a wall in my head and prohibited myself from looking past it.
Nearby, doctors were rushing around, some calling patients’ names, nurses strolling about with syringes, children wailing at the top of their lungs. I couldn’t hear any of it; I was bitter on the inside: unfeeling.
Mom, who sat beside me, took my hand and held it gently in both of hers. I didn’t look at her, but I didn’t pull my hand away. Her skin was just as icy as mine. Out of the corner of my eye I could see her eyes were closed, her head bowed, silent tears running down her cheeks. Her dark hair was ruffled and there were circles underneath her eyes.
“Linda.”
Both my mother and I glanced up at the reassuring voice of Dr. Bane. He called Mom by her first name; they knew each other well. I was hoping to see a smile on his face, the smile that had always reassured us, but his expression was a mask of unhappiness.
“Asher’s gone.”
It was amazing how two words could change your world entirely. But these did just that—they sent this planet spinning so I was momentarily blind.
Mom lost it. She broke into sobs at the look on the doctor’s face and fell to her knees, pounding her fists on the ground. Patients looked at her, but I didn’t care. I stared up at the doctor, the man who had always brought us good news, and felt an unfair hatred welling inside me.
Was it because I envied him, envied that his family was safe at home with nothing to worry about, with no disease that could cause them to die? Or because I was angry he couldn’t do something—anything—to save my brother’s life?
Dr. Bane bent down by Mom and patted her back awkwardly, unaware of the nosy patients watching the scene with interested eyes.
I stood. I walked past them where they were huddled on the ground, Mom weeping into the doctor’s shoulder, and down the hall. I knew where his room was.
But I didn’t shed a tear. I walked like a robot—unseeing, empty, like a zombie. Some nurses shot me worried looks, but I didn’t return any of them.
Room 411. I pushed the door open and walked inside, shutting it gently behind me even though I knew I couldn’t wake him.
Then I turned to my brother.
He was sound asleep on the bed, tangled up in tubes that went up to his nose and inserted at the crease in his elbows. His whole body was slack and he was breathing evenly, his bare chest rising and falling slowly. Nearby, a monitor was beeping. I took the stool by the side of his bed and sat down, staring down at my brother, memorizing the shape of his face, the line of his lips, his closed eyes, so I would never forget them. How I wished those eyes would open, how I prayed this was all some terrible trick of fate and a moment later he would stir and that vibrant smile of his would spread on his face.
But he didn’t wake. He lied there motionless, and I was just as still, listening to his breathing, because it would be the last time I would hear it. I brushed my fingers along his bare head, along his soft cheek. I refused to cry, but I could feel the tears coming.
A horrible thought crossed my mind. Asher was never going to experience life. He was never going to graduate high school. He was never going to get married or have children or make me babysit them when he was busy. He was never going to smile again, or open his eyes, or feel the cool rain on his cheeks or the sun’s warmth. He would never barge into my room uninvited again; he would never make fun of how short I was or call me names to tease me, or embarrass me at school events.
And as I much as I knew I hated some of these things that he did, I couldn’t bring myself to say I’d rather live without him.
I wasn’t sure how long I sat there, cradling his head in my arms, but eventually the sound of a door opening alerted me.
“Julie, hon,” I heard Dr. Bane say. “We’re about to end it. He’s been in pain too long.”
I rested his head gently on the bed as my mother came to kneel beside him too. Her son, almost grown-up, hardly a year away from college. My brother, who I’d known from the moment I was born, the first person who had held me, the first person who I’d ever felt such an ache for.
“He’s on sedatives,” Dr. Barnes informed my mother. “But he’ll be gone once we shut off the machine.”
I stared down at my brother. I had expected this moment to