Hi Emma
I'm 47 and have spent the last 27 years working in a career that has been very successful. Funnily enough MY anxiety made me a great employee, I never missed a deadline, was always on time and my work was always perfect. Eventually though I ended up with a nervous breakdown!
Let me reveal a secret that no one tells you when you first decide what career your interested in. The secret is the vast majority of people in life end up in a job they hate, purely for the pay, or stumble into a career nothing to do with their degree or college course. Please dont be too concerned that things are not quite working out as planned at the moment. The skills you have developed for script writing will put you in good stead for other work.
Job websites and recruitment consultants are a bit like sausage factories, my wife was once a HR director for a large London based company and most CVs went into the bin. Everyone looks the same. Consider contacting some of those friends (or family) of yours, not to pester for jobs but to get them to give you phone numbers for managers in their companies or to meet them for drinks where work colleagues are present. Make contacts and enjoy yourself at the same time. Put in the work,speak to people, pick your time right and you will be surprised what people tell you. Often in life its not what you know but who, sadly. Dont worry about developing your career, just get a job for experience. Where you start out is not where you will finish.
Incidently, are you specifically worried about your career, or just is this just a part of your anxiety? Perhaps you brain is working overtime. Why not sit down rationally with a pen and paper and write down what is concerning you and then see if these are justified or blown out of proportion. A good App that helps is called iCBT.
Hope this does not sound too patronising
Good luck