I agree with Liz that if you are signed off sick, you can't ignore that and return to work unless you are fit to do so.
I'm so sorry you had a dreadful time and an insensitive doctor at your medical. I'm shocked that she would ignore, or not even bother to read, information given by specialists about your condition. However difficult it is, and with mental health issues to deal with, I appreciate that being assertive is really hard, I do think you have to appeal against the decision, and get as much support as possible to do so. A strongly worded letter from your dermatologist might help. Sometimes the CAB can be helpful in supporting people with benefits appeals.
When we applied for DLA for our daughter Nina who has EHK, the claim was turned down initially; they said she did not require significantly more care than any other baby. How wrong could they be?! We got it on appeal though, so don't give up. Good luck!