Loses due to nervousness, hope sucks almost; terrible (6,2)
I believe the answer is:
chokes up
'loses due to nervousness' is the definition.
I can't tell whether this defines the answer.
'hope sucks almost terrible' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'terrible' is an anagram indicator.
'hope'+'sucks'='hopesucks'
'hopesucks' with its last letter taken away is 'hopesuck'.
'hopesuck' anagrammed gives 'CHOKES UP'.
Can you help me to learn more?
(Another definition for chokes up that I've seen is " Becomes emotional".)