It's my disorder that makes things so hazy (5)
I believe the answer is:
misty
'hazy' is the definition.
(synonyms)
'it's my disorder' is the wordplay.
'disorder' is an anagram indicator (a disordered version of the letters).
'its'+'my'='itsmy'
'itsmy' is an anagram of 'MISTY'.
'that makes things so' acts as a 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 misty that I've seen before include "Slightly fogged" , "Old number" , "Dim, obscure, clouded" , "It's not clear" , "Foggy; dim in outline" .)