Speak openly and freely to your nonJW aunt and make for certain you can move right in with her if your parents eject you from the house.
When you have a plan in place spend as much time as you need to completely compose yourself in mind and on paper. Ask to sit with mom and dad. Tell them you need to speak openly, freely and without interruption, judgement or accusation. If they agree to hear you out, calmly and logically explain TTATT and why you are NOT going to get baptized or EVER become a JW in the future.
The Ball is now solidly in their court, isn't it?
They assured you they would not judge or accuse you. Listen to what they say. What they 'offer'. Respectfully hear them out. ( don't interrupt or feed into their emotional pleas ) This is why you must be emotionally prepared to experience the worst well ahead of time.
If they respect you as their child and allow you to be yourself until you decide to leave home, all is fine.
Anything else they may do that violates you as a person, remember, you already have 'the plan' in place. Make the phone call to your aunt and pack your bags.
I would only suggest this if you have already emotionally prepared yourself for a lifetime of shunning... They may have misplaced their own loyalty and an absence of natural family bond or love because of the cult.
Either outcome allows you to "Enjoy life".
I hoped you noticed that. It really is all up to you.
Take your time if you need to.
Choose wisely. You get one shot at life.