I've had excessive to severe swelling from just below the knees to tips of my toes. my glucose is normal and my ana is neg. what could this be?

Salt and no exercise: You are describing pedal edema which is worsened by the above and improved by correcting them. Bad veins ( venous incompaten)could be a great contibuting factor, as can obesity. Lower extremity edema is increased by all these.

Swelling: You need to be evaluated by a vascular specialist that has a special interest in lymphedema. You need further testing and treatment.