Hey Juuves,
I’m not a writer, but I’m working on my first game in the IF medium so take this advice with a grain of sand salt. 
There’s a great 3-part series on writing that I encourage you to read. You might fit the profile of the author or you might not… but for me, it hit all the right notes. (The series focuses on clear and concise writing.)
- Writing Well Part 1: Sensibilities
- Writing Well Part 2: Clear Thinking, Clear Writing
- Writing Well Part 3: Origins of a Writer
The biggest takeaway for me was… having something to say. (Also, there is a benefit to writing terse, effective IF for some stories so maybe that series of links is more relevant than I had anticipated.)
Writing is so much easier when you actually have something to say. The ideas flow. Every sentence has purpose. You don’t lose focus. You support your claim/story with stronger arguments/direction. So I guess, ask yourself, what am I trying to say with my story?
Being able to write your story’s theme in a succinct sentence is invaluable. A developed theme can really keep you on track. Some themes are tried and true (moral truths and such)… and there’s absolutely nothing wrong with treading over a well worn path.
As a side note, I’ve never liked reading. Actually (let me rephrase that), I don’t like reading books. I never could keep the little picture in my brain going. I always felt like I was studying for a test. I hated books… until I found Isaac Asimov. I enjoy reading his short stories because he has something to say in each of them. I especially like his stories because he doesn’t focus on people and relationships. He writes about ideas that encourage reflection and deep contemplation… and the characters really only exist to support those ideas. Ask yourself, what kind of writer are you?