Cant really join in on your rant about Doctors but maybe I have an idea that could help your studying.
A friend of mine used to get severe headaches when she was stressed out around exam times and wouldnt be able to study, but because it was exam time she needed to do something. She started to read aloud what she was trying to learn and taped herself on a cassette as she read. She then would listen to herself on a personal stereo.
Now I know it still involves some reading but it doesnt involve the constant reading over and over of one topic. Maybe you could try doing this… lets face it, if your grades are slipping and reading is a real problem then it cant do anything but help.
And if it is really so bad that you cant read even once, ask a parent/friend/sibling for some help… pick a voice you’ll be able to listen to over and over though.