Mini 11 July, Your question has made me thoughtful. There are two abilities that matter for a teacher of English. One is knowing the language and literature well so that you can create lessons that work to help your students read and write. The other is personal confidence. Do anything that enhances your confidence, from further study and reading to simply knowing that you are good and will only get better.
English and personal development go well together, don't they? Be very interested in your students, I would say. If you ask them questions about themselves, they will want to communicate, which is the first part of writing or speaking well.
I still teach, in that I present writing workshops for adults. I tell them that grammar rules and all such only matter because they help you communicate. Anything you say or write has to REACH somebody and get your idea across. That's the point of all talk and all of literature, right?
Let me know if this is helpful. Ask me more questions if I haven't spoken to your concerns well enough here. And bless you for doing that work you do.