I'm returning to doctor awfully tiny photograph (8)
I believe the answer is:
microdot
'tiny photograph' is the definition.
(I've seen this before)
'i'm returning to doctor awfully' is the wordplay.
'returning' says the letters should be written backwards.
'to' is a charade indicator (letters next to each other).
'awfully' is an anagram indicator.
'im' back-to-front is 'mi'.
'doctor' anagrammed gives 'crodot'.
'mi'+'crodot'='MICRODOT'
(Other definitions for microdot that I've seen before include "Small amount of drug" , "LSD tablet" , "Tiny photograph" , "Much reduced photographic image used in espionage" , "very tiny shot" .)