Old man committing robbery, and going to pieces (9)

I believe the answer is:

panicking

I'm a little stuck... Click here to teach me more about this clue!

'going to pieces' is the definition.
The definition and answer can be both to do with human feelings as well as being present participle verbs.
Perhaps they are linked in a way I don't understand?

'old man committing robbery' is the wordplay.
'old man' becomes 'pa' (both can mean someone's father).
'committing robbery' becomes 'nicking' (I am not sure about this - if you are sure you should believe this answer much more).
'pa'+'nicking'='PANICKING'

'and' is the link.

Can you help me to learn more?

(Other definitions for panicking that I've seen before include "Acting rashly through fear" , "Losing one's head" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.