I feel that way too. I feel like not having the career "I should have" by now means that I'm a failure or that I "should" be able to do more (be more efficient and more active) at this point. But when we use the word should we're setting up expectations and putting pressure on ourselves that is unnecessary.
Instead of thinking about what you aren't ready to do yet, remind yourself of what you are doing and have done (no matter how small). And instead of beating ourselves up and taking things personally (e.g. "I'm a failure"), don't forget that there are other factors at play too. If you were unable to find a job for instance I would point out that the economy is not exactly thriving right now, which makes finding work harder. Technology is automating things that used to require humans, which leads to fewer jobs. Things like this are out of your control and as such you can't blame yourself for them. And finally, after you come out of your anxiety funk you'll be a much stronger person and most likely do a better job than you may have been previously capable of!
You are so right Fugs. We have to keep that in mind too. The job that I lost was not the kind of work I was doing, and then getting pushed off made me angry. But I better just forget that and try to concentrate on getting well.