Don’t get stuck on the grammar. You’d be surprised how many people don’t realize grammar isn’t even a thing you should care about. All they know is whether or not something sounds right.
Read it aloud. Does it sound right? You’re gonna be fine.
Not sure? This is why you have accountability partners and a trusted group of readers you can run things by. Grammar anxiety is all in your head. You have to make the mistakes on the small stage before you can book the bigger shows. When in doubt, show your work to your significant others - they are excellent at pointing out flaws.
The one surefire way to see a grammar mistake? Hit the publish button. Someone else will gladly let you know about it. Some people make it their job.
Start small and work slow. Shorter sentences invite fewer errors.
Grammar is difficult to teach, especially to adults, because you already know grammar. Language is wired in from a young age; it’s how you’ve survived the world this long. You may not know how to make something right, but you can sure tell when it’s wrong.
Further reading on Grammar
Worth bookmarking, buying, and keeping on hand for a monthly read through: The Elements of Style by Strunk and White
Worth having a desk copy: Dreyer’s English
A slightly askew take on the absurdity of English grammar: Eats, Shoots, and Leaves
The Grammarly blog - even if you don’t pay for their premium service, they do some exceptional work on their blog.