I think there's a difference between googling your own condition and disparaging your doctor as OP seems to be doing.
I agree that doctors should listen to their patients, and also that patients should advocate for themselves.
All doctors are taught the difference between signs (observed, measurable) and symptoms (reported by the patient, subjective). Both are necessary to accurately diagnosis - though again, many illnesses can produce very similar effects on the body, so GPs are taught to assume and treat for the most common illnesses first, working their way through less common ones as prior treatments fail.
It sounds like your doctor ignored visible signs (facial clues) relying only on clinical tests, which is very poor practice.
But to revert to the "normal" theme It sounds like your face was "abnormal" during a flare and you could see that. If your doctor has never seen you at a healthy time that face may well seem normal for you unless you are reporting that change as a symptom. It is one of the things we seem to have lost, having a GP that knows you over the years rather than a new doctor on each visit to the surgery, and who can therefore detect those differences in you themselves.
I agree with you that the Internet has become a very useful resource for patients and GP's alike but some of my medical friends lament the fact that people present with their own 'certain' diagnosis instead of reporting their own symptoms, or (now knowing the symptoms for their perceived condition) then overemphasise those symptoms to the doctor.
I'm glad you finally got treatment for your condition. It saddens me that you've had to suffer so long.