Introvert by temperament but I have to move through the world most of the time like an extrovert, due to the nature of my work and the needs of people around me. It can be pretty mentally-exhausting. I know myself well enough to know what's needed to re-charge though, so I manage OK.
And I've never been troubled by shyness, anxiety or depression or other issues that could make things more difficult. I don't dislike or distrust people - I just simply feel happier and more productive when I have lots of time alone with my thoughts, and I only really ever relax when I know there's nobody who needs/wants anything from me at the moment.