Not manage to think straight, so find nothing to go with gin (2,3,2,2)

'not manage' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'to think straight so find nothing to go with gin' is the wordplay.
I cannot quite see how this works, but
'to' is present in the answer.
'nothing' could be 'o' (O resembles 0) and 'o' is located in the answer.
'go' could be 'fit' (synonyms) and 'fit' is located in the answer.
This explanation may well be incorrect...

Can you help me to learn more?