That sucks! When you put in A effort and your transcripts don't reflect that, it's an awful feeling. That being said...
You are absolutely, irrevocably 100% responsible for your own education. If the instructor never showed up for a single day of class, it is up to you to utilize all resources to learn the material as thoroughly as possible. The textbook is one way. The internet is another. Tutors are another. Study groups rock. Most schools
offer learning/answer centers with tutors who are specialized for the course. Locating former classmates who are familiar with testing format and have great advice are another. It seems you take advantage of many of these already, but when you're a few points shy of an A, take a long, hard look at yourself and ask if you truly used every last one. There is always something you could have focused more on, or an avenue you didn't explore.
Sometimes, you can learn the material precisely how the book states it, but in practical application, you aren't as sure how to exercise concepts as you think. With chemistry, this can be especially true, and oftentimes, inevitable.
I know it might be frustrating, but consider this prep for the futility of "select all" and situational applications of knowledge in nursing. Unless you've taken nclex-style tests before, I can't express how ridiculous, confusing and soul-crushing it can be to do EVERYTHING you're supposed to do and more, and still barely muster a B.
Your instructor may very well be worthy of blame. However, this line of thinking will not help you when it comes to nursing. You *HAVE* to learn new ways of learning and reinforcing information. Tests aren't designed for people to get an A...they exist for you to fight tooth and nail for a B. Your standards are high, and that is AWESOME. Don't lose that. But also understand that you will be a more successful nursing student if you adapt to the rigors of a curriculum that is completely different from "memorize/regurgitate verbatim."
Good luck to you, OP. Drive and determination are things you can't "teach" someone. You've either got it or you don't, and it appears as though you have it in spades!