Either your mom has been having doubts and was truly and deeply shocked by the realization of what they really teach, OR she is emotionally blackmailing you. (See what you've done? You've pulled me away from the truth which is my love and my life and now I have nothing left).
Or it could be a mixture of both. Obviously, she is shooting the messenger here. She might not be mad at YOU, chances are that she is mad at herself. Don't feel bad, it is NOT your fault.