Best wishes for a swift and full recovery. Pneumonia is most unpleasant.
Same happened to me at the end of August. Unwell for 5 days inc a negative COVID test. Then a visit to local GP who prescribed cheap antibiotics (amoxicillin), which did not work followed by A&E where I was admitted to a non-COVID respiratory ward for three days. They used drip delivered stronger antibiotics, which did the trick. A very scary experience (wife waved goodbye at the door, please don’t send him/me to the COVID ward etc) and it took about a month to get over it. No idea what caused the pneumonia in the first place although suspect I may have had COVID mildly back in March.
Chris