Hi.
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain
metallic taste in mouth can be due to infection in the
salivary gland leading to discharge of infectious fluid known as Pus and it can be a common cause of metallic taste in mouth..
Other causes of metallic taste can be side effect of any medication, dental and
gum infection, acid reflux,
post nasal drip etc..
As you are having
sinus headache there is a possibility that you also have a post nasal drip..
Also as you take a number of medication, therefore it can also be due to side effect of medications..
I would suggest you to consult an Oral Physician and get evaluated and a thorough clinical evaluation can be diagnostic..
As of now you can take Diclofenac or Ibuprofen for relief from headache..
You can gargle with warm saline water..
Gargle with antimicrobial mouthwash..
Drink plenty of water..
Chew flavoured sugar free chewing gums..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.