I totally understand this! Non-writers just don’t understand that our fictional characters develop their own force of will that bends a plot in the direction they want. In my first novel, I wasn’t intending on having any main female characters, but out of the blue a woman reporter marched into my office, planted her feet on my keyboard, and demanded, “You WILL write me. You don’t have a choice in the matter.” And she has thus played a main role in every chapter and given my protagonist living hell for much of the story. And right now I really don’t like her very much, but there’s no getting rid of her!