ANONYMOUS - NIce to have you here ! Welcome to the board. I was born and raised in the Witnesses from birth also- but didn't exit until age 44 about 12 years ago. DON'T be THAT me. ( Like the commercial )
Do you have ANY relatives or good adult friends outside the JW religion who would be a support system for you and help you make plans for a college education ? It's important to finish High School and apply yourself to learning and once you start college studying subjects you are interested in- college will HELP you expand your thinking ability to develop critical thinking skills needed to survive in the work world and the REAL adult world - not the fictitious JW world.
Also Freemindfade 's advice is great about continuing to do more and more research on the Internet so you will be making an informed decision about not joining the Witnesses. It will solidify the doubts you already have in your mind by seeing that the doubts ARE reality and extremely valid.
Be respectful to your JW folks- but that doesn't mean that you have to go to mind numbing meetings. As you turn 18 you'll need even more support from non-JW friends and family so I recommend feeding those relationships in a positive way as there will probably be a fallout and negative reaction from your JW folks and their friends for your decision to NOT be a JW. So these are just some things I can think of. We are here as friends to you also and as a support. We've " been there, experienced this " so please know that you are not alone, O.K. ? Hang in there take care