I am sorry to hear that you have been dealing with a cough and now have laryngitis, and that it has obviously negatively impacted your quality of life. And understandably so. I hope that I can give you some information about laryngitis which will be helpful to you, and that I can recommend the appropriate physician for you to get evaluated by. Since I can't take more of a history from you, or examine you, I am going to recommend that you make an appointment to be evaluated by an ENT (Ear Nose Throat) physician. It sounds to me like you may be suffering from an upper respiratory tract viral infection, or URI (often referred to as a 'cold'). The viral infection will cause inflammation and swelling of the mucosa (lining) within your nose and mouth. This inflammation causes pain typically as well, and can result in decreased oral intake (because it hurts to swallow). This ultimately leads to thickened mucous. These sequelae of the viral infection will not only affect the sinonasal cavity, but also the throat and larynx (voice box). The combination of swelling within the larynx, and thickened mucous disrupts the normal mucosa wave of the vocal folds and causes dysphonia (abnormal voice). If it becomes bad enough, it can result in aphonia (or lack of voice). Dysphonia secondary to a viral infection will typically resolve a few weeks after the viral illness
is gone. This can take a long time to go away, because swelling in the vocal folds takes a long time to resolve. An ENT will be able to examine you and tell you if this is in fact what is going on. Best of luck.