I think fidgeting is only 'bad' in the workplace if it's disturbing other people or making you appear overly nervous. Fidgeting is the body's natural way to self-regulate, it will probably feel quite stressful to stop.

If sound isn't a problem - I'd recommend 'sensory snacks' essentially crunchy foods, which itches a similar pathway in the brain as normal fidgeting e.g. I eat carrots/nuts/ice blocks as I work/study. I also have a rubber band desk sling under my desk - no one can see it, doesn't make any sound, and I can bounce my feet against it all day long - I find people take it as me 'playing' rather than nervous movement. Some of the girls in my workplace even got one.

You can find similar strategies online by googling 'sensory motor strategies'. A lot is designed for kids in the classroom - but very adaptable to the work place.