Many (most?) of my clients have a huge amount of anxiety associated with career change. This is something I know well myself - my mind has the capacity to get stuck on one long anxiety loop.
The next question I get asked is whether it's a problem or not. Difficult one. With other illnesses, we can safely say there is no 'right' amount to have. But with anxiety, how do we know what the 'right' amount is? None? Are you sure?
There are some basic checks we can make for depression surrounding sleep, appetite and exercise. But for other mood disorders people want help exploring, so I wanted to show this potentially helpful site which tries to identify the level or severity of mood disorders.
Of course, this is no substitute for a visit to a GP, but there's lots of dodgy information out there - this is a good first step before going to your Doctor.