Sadly girls your story isn't a new one.
Every nursing or pre-nursing student who feels she/he didn't get the grade deserved has a reason (and I'm not blaming anyone), and both the nursing department and others have heard all this before.
If the teacher is truly that horrible, and the entire class rises up and takes action, then *perhaps* something can be done. That is still a very big *perhaps*, as colleges/universities do not by and large like reversing grades. I mean they cannot force the instructor to submitt different grades.
Hunter College has a very clear grade appeal process. If have done so and a decision was reached not in your favour, there is nothing to do but move on. OTHO, if you haven't gone this route, then it is the proper place to start.
If you can repeat the chem class with no harm to your standing (provided the next grade is above a "D"), and application to the nursing program, then that is really your only option. While both grades will remain on your transcript, and that "D" will hurt your overall GPA, you need to find out if the nursing department will look at both grades, or just the highest. Also find out if repeating this science course uses any options given for future "problems". Most nursing programs
have strict limits on how many classes a student can repeat.