<human>: Can you condense the text into a few key points?

I know a lot of people claim to be so introverted that they can't talk to people, but I have a slightly different problem, and I don't know how to fix it. When people try to talk to me, like if someone I know sees me at work, I get panicky. My heart races and my hands go numb, I can't think, and I get fidgety. It's like the beginning of a panic attack. And it's not like I just get anxious. 

I feel like I come across as overly smiley (to try and lighten the conversation) and awkward. I never know what to say. My smiles are just to try to be inviting, but I end up just scaring people off. How do I fix this?
<bot>: My overly happy appearance is freaking people out. It's just a cover to try to interact with people without having a panic attack.