Many people feel that this is one of their objectives as writers. I disagree, unless your interest in grammar is a soulful journey. But I believe that most people experience a pure feeling of incompetence and guilt over not writing in a grammatically correct way.
I have a different view on this. First of all, please don't talk to yourself as if you were a kid in school about to get a bad grade, ok? Be kind to yourself. And write from your strength, with grammar mistakes (as I'm probably doing right now, haha). I believe that as writers, our job is to recognize the pictures in our minds and souls that wish to be expressed, and find a way to get them out on paper/screen. Grammar is not our responsibility. We can have help from others who are good in grammar, for fixing it up. It can be a service, for example: https://www.papertrue.com/ they are not at all expensive, and they'll help you. I've used their services a few times.