Hi Dear, Welcome to HCM. Understanding your concern. Thanks for your query . The black spots on throat you mention in query are because of chronic sinusitis along with post nasal drips . Sometimes throat infection when left untreated goes down the respiratory track and cause infection to larynx , which is the reason you lost your voice , but this is temporary and you will get back to normal as infection go away . The reason for dark spots in your mouth is most probably due to dental filling specially silver filling , other causes can be hemangioma , melanoma or sinusitis . I would suggest you to consult ENT specialist (ear,nose ,throat) for proper examination and to rule out other causes like any malignancy. Doctor may prescribe antibiotics course or continue antibiotics already prescribed by doctor , nasal decongestants or anti histamine drugs. For now do warm saline rinses 3-4 times a day ,take steam twice a day.and drink lot of water . Also consult dentist for faulty restoration and to replace it . Hope your concern has been resolved. Best Wishes, Dr. Harry Maheshwari