What I've always done when i would start to feel anxious, I'd leave my immediate environment and go for a walk or a run. I found that the more anxious i would feel the longer and harder i would run. (I'm not all that physically active either, I sit all day at work and i don't very much enjoy any sports.) Now this method requires a certain attitude you have to develop in yourself. I found when i was worrying about something i would run until i was tired. The next day I would usually feel a thousand times better. Not only had I overcome my anxiety, I had also made myself feel better about myself. Hope this helps!