I don't think anyone's able to steal your identity. You are your own unique individual.

If your mother wants to act as a know it all; just think silently in your mind "yes mother dear" but don't entertain a discussion on it.

You don't need to tell your mother everything. Or anything, for that matter. You're an adult.

When the time is right, hopefully you will find a new job and be able to move out of home.