Being put off, I speak pompously and get worse (11)
I believe the answer is:
deteriorate
'get worse' is the definition.
(deteriorating is a kind of getting worse)
'being put off i speak pompously' is the wordplay.
'being put off' becomes 'deter' (I've seen this before).
'speak pompously' becomes 'orate' (I've seen this before).
'deter'+'i'+'orate'='DETERIORATE'
'and' is the link.
(Other definitions for deteriorate that I've seen before include "decline" , "Become steadily worse" , "Fail" , "Become slowly worse" , "Gradually worsen" .)