Both creating and not creating makes people anxious. Best to choose creating then at least you get to have something to show for it. Accept that you will be made anxious by creating. Thats Ok. It doesn’t hurt, its just a bit uncomfortable to be outside a comfort zone.
If you have been procrastinating on that play or book you have been meaning to write, you are just out of the habit. You need to create a new habit and transform yourself into a person who manifests the qualities of a productive writer. As self -actualisation, writing or art-making is seen as the embodiment of one’s noblest aspirations, one of the higher things that human beings are capable of doing, a perfectly natural and healthy thing, a spiritual or heroic journey.
If you have a wish of being more creative, then nurture this wish. It needs your desperate attention. It needs you to be different than the millions of souls who feel it but are not transformed by it into active creators.