You know the hadiths about gentleness. You have tried being more patient it didn't hold. You have tried being firmer something felt wrong. You have taken courses.
The problem is not your intention.
Most parenting content available to Muslim mothers falls into one of three places. Cultural parenting real wisdom about respect and structure, but often without mercy or the Prophet's ﷺ actual practice with children. Western psychology useful in its mechanisms, but with no telos. It cannot tell you what you are raising your child toward. Islamic reminders that the Prophet ﷺ was gentle true, and not enough. You have heard it a hundred times. You have never been shown what it looked like in a specific moment with a specific child.
None of these is complete. None answers the real question.