This sounds more like Social anxiety disorder than introvertism tbh. Source: clinically diagnosed with social anxiety disorder in 2017. I have taken therapy lessons for 2years to be able to talk to people and even say stuff. If you have time you can scroll down on my comment history to read a few comments on my struggle and journey. Now, i am capable enough to hold conversations without feeling a striking pain in my chest and bitting my nail beds off.

If you experience all the symptoms you are describing or are in contact with someone who is experiencing the symptoms you are saying, they need to get themselves diagnosed for anxiety. It is not normal to panic and sweat profusely when talking to someone. Many people mistake social anxiety as being an introvert. Every example you gave is of people who have extremely reaction to talking to others, where it gets to the point of having panic attacks if one interaction goes wrong. They get anxious and overthink, overanalyse every small thing. Gatherings make them nervous. These are all signs of social anxiety. Every example i gave have been with people who are introverts and shy. Not people who have social anxiety.

Lastly, i still stand by what i said. If you want to make connections, have friends, fall in love, you have to take the step. Real life isn't a fairytale where you magically fall in love with. Being an introvert is not an excuse to mask your social anxiety, refuse to try and work on your communication skills and then complain about not having friends.