I been in situations like what the OP described.
I've realized from personal experience that I tried to push all feelings aside so other people can't see my fear, anxiety, embarrassment, etc. I didn't realized at the same time I was also pushing all other feelings, such as affection and I start worrying how I would appear to people. Of course I denied it to myself, but why else would I hide those feelings. I made excuses that when people knows how you feel that they could manipulate you. This denial caused other things to manifested, like it made me harder to know from a personal level and it made me into a person that was oozing negative attitude.
People often gave me advices to not care about what other people thinks. Of course i've adopted that method as well, but the social anxiety did not go away. I still felt awkward talking and interacting with new people. Now, this is the time when i found the personality type indicator. For a while, I accepted that I just worked like that, that socializing is not my thing because i'm a introvert.
Now you might be asking, what is your point? Well, I came into a realization that whenever I'm nervous, it is usually caused by something that is unknown. When you're in a dark room your body is in the alert mode while walking because your eyes cannot see anything. But what does this have to do with anything? Well i told my self that talking to stranger puts me in a position where theres an unknown factor and the reason for my anxiety. But wait, I didn't realized another factor which I neglected and failed to recognized after all these time.
The feelings that i've neglected had become a noise in the background, always there but I never payed it any attention. I neglected it and I didn't realized that it was eating me up. So i've come into another realization, I would embrace those feelings instead of fighting me and notice how it affected me. Robot much right? And i was surprised by the results, suddently I felt like a heavy burden was lifted off my chest. I realized that those feelings never went away it was always there and because I didn't know how to handle it, my body's reaction was to feel anxious. So once I've done this I had become more confident and the conflicts that gave me nightmare suddently wasn't such a big deal anymore. Why? Because those feelings were not unknown to me anymore and I could concentrate on what's in front of me. This also explains to me why my INFP sister was such a natural speaker in public and why she can socialize so naturally even though she is also a introvert.
Well if you manage to read this far, congrats...life story are boring aren't they?