Why am I not good at writing

I was feeling down after writing class because of my bad writing skills. Nowadays I start this course because I hadn't had any opportunity to writing essay before. Our writing course has 45 minutes and we have to write essay until finish till the end. Only 45 minutes are really difficult for me, because I'm not used to writing it easy with. Although I have no choices so I had tackled the writing.
However, when I was struggling to write essay, I couldn't come up with any idea what I want to write. That's why I couldn't finished it. On the other hand, my friends had already finished their writing before finish end of our class so I got depressed.
I'll never forget this feeling. I have to practice my writing more, so I am writing my mind now.
I was thinking about why am I not good at writing while I am getting back home from my school.
Then, I came up with some reasons of for my bad writing skill.
The first reason is I hadn't decided what I'm going to write before starting to write essay. That's why I confused what I want to write, then I was lost my way to write it.
The second reason is my poor memory of correct spelling. Basically, I rely on predictive transform, so I don't need to lean by heart. Consequently, I spent a lot of time to write correct spelling.
The final reason is I haven't got it very well how to create natural sentences. I've already known basic grammar but I'm not used to how to make natural sentences.
I guess these are the main reason of my bad writing skill and I have to care about them these ones when I am writing essay.

Why am I not good at writing?
I was feeling down after writing class because of my bad writing skills. Nowadays I start I started this course because I hadn't had didn't have any opportunity to writing essay write essays before. Our writing course has takes 45 minutes and we have to write an essay until finish before it's finished. Only Just 45 minutes are is really difficult for me, because I'm not used to writing it. Although I have no choice so I had tackled have to tackle the writing.
However, when I was struggling to write an essay, I couldn't come up with any an idea what I want to write about. That's why I couldn't finished finish it. On the other hand, my friends had already finished their writing before finish our class our class was finished so I got depressed.
I'll never forget this feeling. I have to practice writing more, so I am writing what's on my mind now.
I was thinking about why am I I am not good at writing while I was getting back home from my school.
Then, I came up with some reasons of for my bad writing skill skills.
The first reason is that I hadn't decided what I'm I was going to write before we had to start to write the essay. That's why I was confused about what I want wanted to write, then I was lost on my way to write it.
The second reason is my poor memory of correct spelling. Basically, I rely on predictive transform autocorrect, so I don't need to lean learn by heart. Consequently, I spent a lot of time to write with correct spelling.
The final reason is that I haven't got it very well mastered how to create natural sentences. I've I already known know basic grammar but I'm not used to how to make making natural sentences.
I guess these are the main reason of reasons for my bad writing skill skills and I have to care about think of these ones things when I am writing an essay.