1. Is there a psychological explanation for what I'm experiencing? you are special, jk

2. Does anyone have any experience or advice for the matter? yes, see next question

3. Why do people have such a problem when I close off to them? What is going on in their mind?

you're being unsociable, is there any reason for anyone to behave otherwise when you are in such a state?

especially if you are always like that, with everyone, which I assume you aren't