Brush/floss daily what causes the enamal to come off teeth at the gum area, could certain diseases/disorders cause this or what causes it, an what 2 do?

Friction or chenical: Frequently over horizontal brushing with a stiff nylon brush can do this. You are only 42, so maybe not this yet. Some kind of constant acid presence can do this. Foods, losengezes, toothpick poking habits are all possibilities.

First make sure you : Only using a soft or sensitive toothbrush. Also use a normal toothpaste (crest, colgate ...) not one which is overly abrasive ( like a smokers toothpaste). Check with your dentist if you are clenching or grinding, and if so to have an appliance made. Finally be evaluated by an orthodontist if malocclusion exists. Genetics and family periodontal history can also contribute. Hope this helps.