Hello and welcome to hcm forum,
The low blood sugar
level is a sign of hypoglycemia and hypotension.
and shaking are the symptoms associated with hypoglycemia.
I would advice you to get a check-up by a physician.
There is no correlation of the above mentioned symptoms with the tooth to be treated by root canal.
Please do visit your dentist
and get your mentioned teeth root canal treated.
Maintain oral hygiene well.
Take complete course of antibiotics.
Rinse your mouth frequently using warm saline and betadine.
mouthrinse to gargle.