Have you considered eating something every few hours on a regular basis, even if it's just some Celery to keep blood glucose up?
FYI - I get/got the same sensations if my blood Sugar gets too low: nervous, anxiety, shaky, etc.... never really worried about it much through the years but, it was what forced me to eat just to squash those symptoms. Then again, increasing blood Sugar through bad food choices in those years led me to become this ill with candida being a primary symptom so, what do I know.