Slightly numb tense feeling left hand (wrist) and burning tight feeling left lower leg, on and off. can it be from shallow breathing when anxious?

RATHER UNLIKELY: Possible that you could suffer from peripheral nerve issues, such as carpal tunnel syndrome and/or tarsal tunnel syndrome. Underlying metabolic issues may be contributory. Anxiety and shallow breathing are a separate issue, but all needs to be evaluated. See your doctor.

Highly unlikely: But possible. One sided symptoms need to be reported to your doctor as they may be early indicators of more serious isues.

These symptoms: Don't seem related to your breathing or anxieties- see pcp for work up.