Well, I am all of the above.

I have been studying T'ai Chi for years, and it is a wonderful thing. I also am a singer and play keyboard. The singing especially lets me blow out the stress. After a bad week, I can really wail on the blues.

T'ai Chi relieves the stress whenever I do it. I still haven't completely mastered retaining the calm when I'm not doing T'ai Chi. I have improved in dealing with stress but I have a way to go.

Blandry is right. You have to have your mind and spirit in a good place in order to successfully deal with the day's stresses. If I have a bad moment, it's certainly not due to a lack in my T'ai Chi training. It's due to an unhealthy mental state or a lack of mental preparation.