It can be helpful to realize that, as difficult as your situation is, it is not impossible to bear, regardless of how it all feels at the current time. You know that living at home with your JW parents is not "it" for good and that, with planning you will leave and achieve a level of independence in which you can provide your own financial support.
You are in what I'd call an "in the meantime" situation: Before you reach the goal of leaving home, there are some things that you need to either do or bear - and as hard as it seems, there is no other viable course, given you no longer believe JW organization.
Keep in mind, too, that, in one form or another, other religious groups impose strict conditions on their youth - and some such as Islam even stricter conditions that outlaw leaving the religion upon pain of dire consequences in the here and now. This comparison is not intended to minimize your pain, but to help you bear it more skilfully whilst you prepare yourself for life away from home and the kingdom hall. Separating from parents can be difficult at the "best" of times and is all the more difficult when you decide you do not want to follow the path your parents have set for you. This is the stuff of life - it is normal to wish it were not this way, but it is helpful to acknowledge that for untold numbers of young people the world over, it is part of the process of growing up and taking responsibility for themselves.
Become clearer about what you want your life to stand for and make plans towards any goals that can help you.