we took the exam on the same day. if you're going to retake, I'll trade you my PAT, QR, RC scores 😀 jp. but yeah, your science is on the low side...and those are very important scores. so i would consider a retake.
try Cliff's AP Bio, Peterson's AP Chem, and Schaum's Organic Chemistry guides for content review. And then supplement those with Kaplan Subject Tests and DAT Destroyer (which I personally don't recommend - but it works for others) for practice questions. And if you want a book that brushes the facts (or a book for order and construction of the DAT), get the Kaplan study guide as well - but you do have to note that you need more detail than what is provided in this guide. Anyway,with all these materials, you should see a big jump in your NS scores if you're dedicated.
Oh yeah, to top it off, get TopScore. It's a good predictor of how well you'd on the actual NS section of the DAT.