What about trying some coping mechanisms to take a step back when you are at work? This has helped me in the past when I've worked highly social jobs. For example, a couple minutes of deep breathing, listening to a song or take a second to journal (I doodle). This way you can reconnect with yourself without getting overwhelmed with the extroverted culture of the office.
I found that at first it felt awkward to do my own thing but eventually it became more comfortable. I also found that the friends that I did make were more similar to me. As an introvert myself I can spot one across a room, so I bet you are not the only one in your office.