Be full of anger having lost almost everything for sure (6)
I believe the answer is:
abound
'be' is the definition.
(abounding is a kind of being)
'everything for sure' is the wordplay.
'everything' becomes 'a' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'for' says to put letters next to each other.
'sure' becomes 'bound' (synonyms).
'a'+'bound'='ABOUND'
'full of anger having lost almost' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for abound that I've seen before include "Be plentiful, say fish in river" , "Exist in large quantities" , "Swell" , "flourish" , "Have riches perhaps" .)