Check out this post from Writer Unboxed on Anxiety and the Creative Process
Some people are more and some are less prone to anxiety, but at one time or another everyone feels anxious. Anxiety at some level seems to be built into our DNA. The author of of the post cited above, points out that it's actually a protection mechanism, getting the body ready to run or to fight.
There are a lot of things these days that seem to raise anxiety levels that have nothing to do with physical danger.
Email is a big one for me. I can become almost unglued when I get too many emails in a short time and I can't focus on any one of them long enough to respond appropriately and with due consideration.
Social media is another one. I know that online communities are powerful and can be potentially wonderful things, bringing people together from many places and many walks of life. Facebook freaks me out, however. I don't "get" Twitter. It is interesting to follow storms and other events on Twitter. But, I can only stand it for a few minutes at a time. I find my anxiety level rising just logging on to either of those sites. There's too much going on for me. It's like walking into a loud, crowded bar. Some people actually enjoy that kind of thing. It triggers my "flight" reflex every time.
These days there seems to be a general sense of free-floating anxiety affecting our entire culture. The economy may be improving in certain sectors, but it's still bad and people are worried. People who don't have jobs are anxious about finding one. People who do have jobs are anxious about keeping theirs. Everybody I know worries about money: the ones who have money worry about how to keep it; the ones who don't have money worry about how to get more of it; the ones who have some money worry about whether or not it will be enough.
There is no doubt that too much anxiety can impede creativity. I personally waste a lot of time worrying when I could be doing something useful. But, sometimes anxiety can actually help us zero in on areas in our lives where creativity needs to be focused. I tend to write about the things that worry me, whether it be in my journal, or in long, impassioned emails that I send to my wonderfully patient and kind friends, or in fictional format where I make up characters and hand them my burdens so I can watch how they deal with the problems. Naming the thing that I fear doesn't make the fear go away, but it does give it a focus. I'm not afraid of everything, but I am afraid of this thing. That enables me to concentrate on figuring out how not to be so worried about that thing.
A lot of times, the way out of anxiety/worry/fear is not to fight it. It's to go with it. A friend of mine once recommended to me a book the title of which was Feel the Fear, and Do It Anyway. I never read the book. The title alone changed my life. Allowing myself to actually stop and feel fearful or worried, allowing myself to express it in writing or in conversations with my friends helps me to realize that, once named and explored rationally, the hurdles are never as big as they seem while they're lurking in the dark corners of my unconscious. That allows me to have the courage to "do it anyway." The "doing it anyway" is often a very creative process.
In that sense, for me anxiety is often an engine for creativity. It's not as pleasant as the fire of inspiration, but it's more reliable. Inspiration comes and goes. For a worry wart like me, anxiety is always there to draw on. I like the irony of that. It's nice to think that all that worrying may serve a useful purpose.