Hi, Confused:
First of all, I'm so sorry--this is super stressful for your mom, yes, but for you, too. You are not responsible for your mother's feelings but they are understandable. Remember one thing--your mind is your own and you have the right to investigate any religion in a thoughtful, critical way. As far as your questions, it all depends. If you need to live with your mother as a dependent, then you are in a more difficult position than if you are able to move out and care for yourself. If you need to keep living with her, then you might need to pull back and keep the peace for at least a little while.
One great piece of advice I got when I was leaving was this: There is no wrong way to leave a cult (or high control religion). You need to do what is in your best interests. That said, it will be easiest for you if you can start arranging your affairs so that you can live independently, even if that is a year or more off in the distance.
When I started fading, I moved very slowly. I stopped going to the service meeting/school but kept going to the Sunday meeting for quite a while. It's okay to say that you are depressed, that you are not feeling well, that you are stressed out.
Hang in there-it DOES get better!