I need help with this, at English

The sky became dark and low with ominous black clouds. The wind picked up, howling, warning, barking like a wolf in the night. The first crack of lightning pierced the air, and within seconds, the rolling boom of the thunder reverberated overhead. Soon, the rain fell, slow to start, splattering the sidewalks haphazardly. Then, it fell as if from buckets, cascading like a waterfall from the heavens. It pounded on the roof as if it were demanding an entrance. I couldn’t sleep. Again.
Insomnia haunts my nights, fatigue rules my days. The time trickles by, marked only by my clock’s changing, glowing numerals. My mind is blank, where there should be dreams is a heavy blackness. My eyes are as stationary as the silhouette of my bedside lamp. When the sallow glow of the streetlamp behind it becomes white, I know the night is nearly over. I close my eyes and they almost sting, like they’ve been accustomed to staying open.
“Sasha... open... your... window...”

I snap my eyes open. What was that? Was it my imagination? Am I hallucinating after not sleeping?

“Open... your... window... for...asleeping... remedy...”

Okay, now my inner demons were actually trying to tempt me with the thing I most wanted in this world. Sleep. I carefully turn the sheets off my body and wrap them around my shivering body like a protective cocoon. Shaking, I tiptoe to my closed window and open the hatch. Immediately, it swings open and the rain starts to drench me.
I must have been hallucinating. There’s nothing here, and no one is talking. I roll my eyes, wishing I wasn’t so foolish, or gullible, or sleep deprived. I’m about to close my window, when, all of a sudden, I glance a flickering light in the distance. It’s gradually becoming closer, and closer and closer, until I can properly see it.

It’s a whispy, white colour, and it appears to be... a horse? It’s blue eyes look me straight in the eye, and I’m instantly spellbounded. It’s almost like magic, like when I look at it, all my troubles seem to disappear. It softly neighs, and I can’t help but think it’s friendly. I feel special, like the horse came to me, like I’ve discovered it!
In the whim of the moment, I crawl out of my window and quickly hop on the mare. Almost immediately, it rears its head and gallops away from my house in the air.

I wonder where it’ll take me?

Hope this helps!