Why have I started to break out in hives daily? No changes to diet, or grooming products.

Hives. Hives/urticaria are most commonly form some allergen, wither a new food or grooming product as you state. but also can be an external allergen such as pollen, dust, mold, danders, insects, trees, grass, etc etc. Anxiety can also cause a "stress induced urticaria." Try the OTC meds, and if they do not work, get the Dr. to evaluate you. Best wishes.