Feverish anthem, a worry to admit! (3,8)

'admit' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'feverish anthem a worry' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'worry' could be 'care' (eg without a care means without a worry) and 'care' is found in the answer.
an anagram of 'anthem' is 'themna' which is within the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...

'to' acts as a link.

Can you help me to learn more?