I wrote 1,000,000 words through various stories and practice before I found any modicum of success as an author. My earlier works were posted online and received a ton of criticism. Even today, I get criticized quite often.
However. I stuck to my guns. I did not give up. I kept practicing, kept writing, and kept pursuing my dream. I wanted to be an author.
When I first started writing a few years ago, do you know where I was?
I worked a dead-end job at a place that called people on the phone for political surveys, a job where 80% of my coworkers were convicts that couldn't get a better job.
I was homeless and living in my car, making ends meet just barely.
My life was horrid, but one thing saved me from that realm of despair.
And that was my writing.
And here I am now. In 10 days, I'll be collecting a sizable monthly check from Amazon, I have millions of views here on WebNovel for a contracted story, I have a large pantheon of loyal readers, and have found myself a great deal of success.
The best advice I can give you is:
Keep practicing. Accept valid criticism and improve in places you need to, but don't blindly believe every bad thing people say about your story. Many things fall to personal preference. Still, there is a lot of value in reading comments and changing mistakes or things that don't make logical sense.
Do not stop writing. Keep it up. Keep working, keep grinding. If your grammar is poor, look into online grammar courses.
Plot your story ahead of time. Know how it is going to end, know how the current arc is going to end, don't rush in blindly.
It took me years to find success. Don't get discouraged. You got this :)