Ellie, I love coffee too. I still drink it in spite of the GERD, although not nearly as much.
I am concerned about the icky taste in your mouth and throat symptoms. These are common signs of GERD. However, in a way it's good (!) to hear that you had a stomach bug, b/c this may indicate it's something else (gastritis, lingering viral infection that can be treated with antibiotics, etc). GERD is not fun and it's often long term.
Why don't you try limiting yourself to 1-2 cups of coffee per day while you schedule and appointment with your doctor? The symptoms you describe sound serious enough to seek medical advice and treatment. Don't freak; but, yes, please do see an M.D. Hey, that's why you have health insurance, right? To use it when you don't feel well.
Best,
Laura