Okay, I probably can't offer much regarding the current SAT, having taken it eons ago. But reading how you describe yourself, I can SO identify: strong in the Lang. Arts, and weak in Math. Plus, I really always had test phobia. A kind teacher gave me a study guide for the SAT when I was in high school, after I performed so miserably on the ACT (due to anxiety). So, yes, the study guide questions helped in just knowing the kind of questions to expect, particularly in Math. And...I don't think you'll have a problem with the reading and writing parts. The main thing the study books did for me with the SAT, and with numerous standardized tests since then (of which I've also acquired the study books), was to prepare myself mentally in a way that allows pacing and NOT panicing! Taking deep breaths and focusing rather than feeling overwhelmed.

Others here have given you even better advice. I want to know how you are doing with this!
Patty