Carrying the box in, got worried (6)
I believe the answer is:
toting
'carrying' is the definition.
(toting is a kind of carrying)
'the box in got worried' is the wordplay.
'the box' becomes 'tin' (I am not sure about this - if you are sure you should believe this answer much more).
'in' indicates putting letters inside.
'worried' is an anagram indicator.
'got' with letters rearranged gives 'tog'.
'tin' placed within 'tog' is 'TOTING'.
Can you help me to learn more?
(Other definitions for toting that I've seen before include "Lugging" , "Carrying with difficulty" , "Heavily laden" .)