Sorry to hear about your situation. Hope you will feel better soon.

You may want to see if your hotel is able to refer you to a doctor. Assuming that you have travel insurance, you can also call your travel insurer to refer you to one of their "approved" doctors. There are lots of expat in Shanghai and there should be many English speaking ones.

Trust your vaccinations are up-to-date. It's a good reminder that we should always visit the travel clinic before any overseas trip.