Sound like to me your Dr. gave you good advice. From what you have said about how you are feeling you are trying to do more than your brain can handle at this time. I can imagine you are feeling pretty bad about backing off you studies. i know it must be a disappointment to you. However, you can use the time to get stronger and have more energy when you are ready to start again. Take you time to take care of yourself and don't beat yourself up over this. It will all work out for the better in the end. Hope you get to feeling better soon.