I have gallbladder with 0% ejection fraction and no stones and constant pain below rib , which is tolerable, can this cause dizziness and headache?

Gallbladder: Symptoms from a gallbladder condition are upper abdominal pains or pressure bloating after eating with nausea & sometimes vomiting. Dizziness & headaches by themselves would not be expected to be gallbladder related. An isolated hida scan finding without other identifiable gallbladder symptoms may not have much clinical meaning.

No: This should lead to you having your gall bladder out.