In the last week I felt a lot of anxiety because I procrastinated an important task. As long as I consider that task to be important and don't do it I will feel anxiety and meditation won't solve the issue.

To get rid of the anxiety I have to either completely the task or make a decision that I don't consider it to be important. The task itself won't get done by sitting down and meditating. It actually requires action.

What meditation can do is that you get aware of the reason why you feel anxiety and give you awareness of yourself. If you want you can let go of all goals and sit all day in meditating in some monastery without any anxiety. If you are on LessWrong that's probably not your goal.

When I'm waiting in the train station for a train than I often practice my Salsa dancing turns. I don't feel anxiety if someone watches me because I'm not attached to impressing a random stranger. There no unconscious desire to impress the stranger that causes me anxiety because I don't fulfil that unconscious desire.

Most of the anxiety that I feel is due to not living up to standards that I set for myself.