If you want to change it, practice yoga. Seriously. I pace plenty. It's ungrounded energy. You're flitting about because you're not centered physically--meaning that your body is not able to sit still because you are not allowing gravity's natural pull to center your form. Sit your ass down in a yogic pose (cross legged or half-lotus) and focus on keeping your core stable, shoulders down and relaxed, neck long, and your head held high. You will use a shitload of energy just trying to keep your form stable. You might shake if you're not used to it. But this will burn off the energy that gets subconsciously expressed via nervous habits.
Honestly I don't mind pacing, and I don't bother correcting for it when I'm alone, usually. But, it really does make other people nervous, which in turn makes me uneasy because I become aware of how chaotic the energy in my form is being when other people are around to mirror my energy.
You could say that I'm nervous by nature and don't mind being nervous for the most part, as I'm sort of used to it, but it can be really hard to settle my mind if I can't center my body, and it all can add up to sudden unexpected shifts into anxious states. Sort of like I was actually already acting anxious but didn't notice it. Basically, between the extra muscle tension necessary to hold up the form when not centered, and the endless barrage of thoughts that tend to accompany my pacing, it's just a stressor on the body that I don't need, so I'm learning to rid myself of it.
