I'm sorry to read that you are having serious doubts about law school but it is far better to have them now when you have the luxury of time to check out if it is more than just cold feet. Also, you haven't committed money yet (besides the 17 million for the LSAT and app. fees) so it would be a lot easier to pull out now then after you've signed the loan papers for law school.
You might consider checking out the book Should You Really Be A Lawyer?: The Guide To Smart Career Choices Before, During & After Law School
by Deborah Schneider, Gary Belsky
I looked through this book and it helped to solidify in my mind why I'm doing what I'm doing. My only reservation with the book is the quiz results. Should you look at the book, take the quiz and read the responses but don't calculate an overall score. The methodology is flawed (you actually get points for wanting to go to law school for the wrong reasons and can score higher than if you want to go to law school for all the right reasons).
Also, have you spoken with practicing attorneys? Or even someone with a JD that isn't practicing? They may be able to give you a perspective that others cannot give.
If you're still not sure, I'd agree with those who suggest deferral.
As the start of school approaches I, too, am getting rather nervous. I'm excited but also scared that I will not have the stamina to do all the work. Among other fears, I'm also concerned about the impact law school will have on my marriage. Not small matters. In the end, I keep coming back to the fact that there's nothing that appeals to me more. Through life I have learned to trust my gut. My gut, though filled with butterflies, says go to law school. If later I decide that the price (monetary or otherwise) is too high, then I'll reevaluate my decision then.
Trust your gut and good luck with your decision.