I think I have Flouride overdose?

My gums and mucosal lining at the floor of my mouth easily gets wounded when I brush my teeth or eat crackers, but I don't have cavities so it can't be gingivitis. I notice that everytime I used oral preparations with high-flouride content, this signs appear. So could it be flourosis?

Also, can anyone tell me what are the causes of non-bacterial gingivitislike what mineral/nutrient deficiency if it were from malnutrition, or what systemic disease does it suggest?