Stop using the toothpaste.You may be allergic to fluoride or other ingredients found in the toothpaste.
Wash your face with a mild and bland cleanser like cetaphil and do not unnecessarily touch or manipulate the area. Apply a sunscreen with at least an SPF 15 in your face and in the absence of redness, peeling or itchiness, you may exfoliate gently before applying a light moisturizer.
If the dark spots (are these spots?) persist, I suggest you seek consult with a dermatologist.Laser therapy and chemical peels may help with the dark spots if topical medications prove to be ineffective.