As per thread title.
How you do it by calming yourself down?
For non-medical anxiety conditions, I recommend drinking a nice warm cup of chamomile tea. Add some honey, and you are calm in minutes. I used to work in a Japanese MNC in Science Park II and the stress was quite high, so I would walk over to A*STAR and grab myself some chamomile tea, then take a short nap in the lounge.
The last time I was medicated for generalised anxiety disorder was in 2001 when I had a bunch of stomach tics. It was diagnosed by the Mindef psychiatrist and they fed me 2mg Valium every day. It worked miracles, but it came with withdrawal symptoms when I stopped taking medication. Eventually I was released as the tics disappeared, and I weaned off the medicine.