Hi and Welcome!

It sounds like you are just starting your journey out of the cult. This forum will be a great place to get advise and vent as you go. As far as a DA letter I think short and sweet would be just fine. If you want to add reasons for your leaving to get your point across you can. I know you mentioned leaving is going to maybe cause you to be kicked out of your parents home. So I have to ask: Are you sure a fade won't work for you?

Fading is difficult if you want to celebrate holidays or do other practices openly that could cause you to be Df'd but other wise you maybe unaffected. I'm Df'd and have lost a lot so I say from experience...." think this through." If you decide it is right for you to DA...I would recommend having a plan. Get a room mate an apartment or set up living arrangements with a non-JW family member. You will need a safety net if your parents flip out.

Take Care of you and don't cause yourself any unnecessary pain. I wish you the very best.

Brandi