Foul Taste In Mouth, Cough With Excessive Phlegm After The Loss Of Loved Ones. Colonoscopy, Blood Tests, BP Normal. Treatment Advise?

My mother is 75 years old. In October her sister passed away and 5 weeks later her brother passed away. She was very close to both of them. Since their deaths she has had a horrible taste in her mouth and coughs up large amounts of phlegm throughout the day, it is especially worse in the morning. She has been put zythromax, prednisone , and claritin. She has had a colonoscopy and a scope down her throat (no signs of an ulcer ). All tests have come back just fine. Her blood work has been fine as well as her blood pressure . She has lost some weight because she says nothing tastes good and all her food and drinks taste bitter. Her first doctor thought she maybe had copd or emphysema but they have offered no follow up. She said she feels like her sinuses are blocked as well. We have no idea what is going on and we are not getting any answers, as she has been shuffled around but no one seems to know what is going on. I have heard that extreme grief can seriously affect the lungs and a persons physical being. She has no chest pains, trouble breathing etc...No idea what is going on but she is very tired of going to the doctors and having them guess at what her condition is or not offer any insight....Should she see a ENT or pulminology specialist?