CW,

I think you weak legs is just a perception. Your anxiety is causing you to sense things that you never paid any attention to previously. Get the pedal system so you can do some basic blood circulation work.

I have been stuck indoors for months due to freezing weather and ice. It does not take much time or effort to regain the small losses in conditioning. I have done it many times.

Get some movement, not exercise. No need to push. This is a part of your anxiety at work. You may be dopamine dependent. Maybe a script of amantadine can enhance your dopamine receptors.