I'm sorry to hear about your frustration with your current situation - it's quite understandable. Many of us have walked your path and later successfully made it out. I'm going to say some of the same things everyone else has, but hopefully it's helpful to hear some common things emphasized and it will show how important they are. Education is the first thing, make it your top priority. You cannot imagine the doors it opens for you in your life until you see all those that remain closed without it. You will be far happier if you pursue it while you are young and better able to dedicate yourself to it. Youth has the advantages of stamina, enthusiasm, and the ability to absorb information quickly. Ironically, this is why the JW's doggedly pursue their own youths to focus "on the kingdom" - because they recognize the value of the previous statement. It is easier to indoctrinate someone when they are young and a "clean slate" so to say. Learn to utilize critical thinking and logic to evaluate the things you are taught, the things you read, and the things you experience. I have a couple of websites that will help to introduce you to these concepts:
Also, as difficult as it is at your age, try to keep the focus off of guys and on yourself. Don't get deeply involved with anyone so that the course of your life is forever altered by choosing to pursue a relationship with them. That's not to say that the outcome of dating someone will always have long-lasting consequences, but it certainly can, especially if you have been raised to believe that dating is is a process by which one evaluates another as a marraige prospect. It can eventually lead to that stage, but it should not have such gravity for some time, especially not at your age. Be free and get to know yourself and your needs, your hopes, your dreams, and your desires so that you can better know who will make a good partner to you and you to them. Start a list of qualities you need in a partner, those you want in a partner, and those which are completely unacceptable. Keep the list updated over time, adding and deleting as necessary. Evaluate anyone you start to seriously date against it and see how they measure up. (Of course, don't tell them about this! LOL) ;-) Love and lust make us do some crazy shit, so while you aren't consumed by it with a particular someone, make your list, then check it twice, and then pull it out if you start thinking, "this is the one!" and see how it looks.
Finally, if you leave the religion, you will have to face the reality that your parents may shun you as a consequence. Prepare yourself for the possibility. If it doesn't happen, excellent, but if it does, you will at least be partly prepared. I'm fortunate in that my parents are no longer in the religion either. However, I have had to deal with other shunning (I'm DA'd) and I find that recognizing that it is the other person's CHOICE to do it and not that I am evil (well, OK, sometimes I might be, just a little...) >;)~ does help. To be honest, I'm to the point now where it means so little to me as to not affect me.
You have a tough road ahead, but it's well worth travelling down in order to live your live as a free person. Hang in there and keep your chin up! :)