I recently found out that the cause of my chronic back pain is herniated disc in my t10-11. Today I have been in a lot of pain but then for the first time I have numbness in my left arm down to my pinkie and ring finger and numbness down my lower left leg and little toe. Then I just started feeling light headed and my teeth/gums feel numb?
Dear patient Your thoracic disc prolapse may lead to back pain and numbness in left side of lower limb and toe.  But tingling and numbness in upper limb cannot be explained by disc prolapse in thoracic spine level.  Are you having tingling and numbness in left side of body okay or its affecting all four limbs?  If latter is the situation vitamin B12 deficiency may be responsible for your symptoms.  This needs to be ruled out. I would advise testing for blood levels of vitamin B12 from reputed laboratory nearby you.  Meanwhile, start tab regain plus vitamin B12 at bedtime for pain relief. You need to consult expert spine surgeon with report. All the best.