My right eye keeps watering. i woke up with crust in my eye. i think it's allergy issue. what should i do to fix it?

Herpes eye infection: Unless you are allergic to your bedsheets, the cause of a unilateral crusty, watery eye with itching is more likely a bacterial superinfection. However, with the history of a cold sore (a herpes virus type i reactivation) you really should see an ophthalmologist urgently to rule out herpes keratitis. This might be serious. The diagnosis can be challenging, so the eye-md is your best choice.