Think e.g. ham sandwiches fine? This makes me despair (4-3,6)

'makes me despair' is the definition.
I know nothing about this answer so I can't judge whether this works.

'think e g ham sandwiches fine?' is the wordplay.
I cannot really see how this works, but
'think' could be 'feel' (feeling is a kind of thinking) and 'feel' is present in the answer.
'ham' could be 'actor' (ham can mean a bad actor) and 'actor' is found within the answer.
'fine?' could be 'bad' ('bad' can be similar in meaning to 'fine') and 'bad' is found in the answer.
A single letter 'f' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...

'this' acts as a link.

Can you help me to learn more?