Thanks, guys! Your explanations make a lot of sense.
Red Panda, that's exactly how I feel! It is less about fear and so much more about inferiority. I may not even necessarily feel anxious in a given situation, but I will feel inferior, like I better not speak, my words don't carry value anyway, I'm in the way, etc. It's definitely about showing emotions and thoughts, I never tell people the truth because I'm afraid of either rejection, misunderstanding or them taking offense, but less about embarrassment. And you're right, it matters so much that someone with authority agrees and confirms that you're not making stuff up.

Hoasis, I really am! I have -avoided- such confrontations before: talking to psychologists, doctors, getting help and diagnoses, and this time I am finally daring to come out of my cave and admit to someone that I have problems (I have a tendency to belittle my problems and sweep them under the rug). But now that I'm finally in that situation, my anxiety is up; I am so afraid of feeling misunderstood and getting the wrong diagnosis. The doctor I spoke with nearly said I had ADHD, because I mentioned my concentration issues (due to stress and depression). I am just afraid of a doctor saying it is less severe than it really is and the rest will be me feeling like a hypochondriac. But you're right, that WOULD be the easy assessment (social phobia)!
And what you describe is exactly what I feel!! I've overcome so much in terms of anxiety, but I just KNOW it's more than that. It's really hard to put words on. It's just more than fear of people. Just because I can go up and talk to people doesn't make me part of them and doesn't make me be able to open up and be me, to be emotionally exposed. And yes, wearing masks and avoiding confrontations, even with people you'd usually be socially comfortable with..

Thanks for giving me more ways of describing this distinction and the way I feel . Really boosted my mood that someone understands.