Welcome!
My best advice (especially since there is just the one post from you), is to not say anything to your mom just yet. Take your time. There is really no need to rush anything.
Be respectful to her - especially if you are still living in 'her' house...!
Regardless of what you ultimately decide to do with the JW's, get a good education - as much as you can - and start saving your money. If you can both work and go school and still have your parent(s) support you, do it for now.
Solid education and a healthy savings account will be the two best things you can do for yourself. They will have long-lasting benefits. Especially with no 'New System' around the corner.
Congrats on figuring it out at a young age.
I look forward to hearing more from you.
-Aude Sapere (meaning: Dare to Know; Dare to Have Wisdom/Understanding; Dare to Think for Yourself.)