Did my professor properly accommodate my disability?
I'm sorry you were ill.  "Extra time" usually means that one has additional time to complete an exam.  For example a student with accommodation might have to take a final exam on the same day as her colleagues, but might have three hours instead of two to complete the exam.

At the two institutions where I've taught, there's a very formal process for notifying professors of accommodations, in which the professor actually signs for having received a copy of the accommodation letter.  I can't tell whether that was at work in your case.

The disability coordinator at your school is the one person who should know exactly what accommodations you were offered.  Your next step should be to see the disability coordinator, explain what happened, and ask whether you were treated according to the agreed accommodation.  If you were not, then either the disability coordinator will work through this or you can use the disability coordinator's statement in your grade appeal.

If you were granted the accommodations the school prescribed, probably you should file that grade appeal anyway, but do not be too hopeful.

I wish you the best of luck in your academic career and in your health.  I haven't read "How to pass organic chemistry" yet, but I will.