It’s my disorder that makes things so hazy (5)
I believe the answer is:
misty
'hazy' is the definition.
('misty' can be a synonym of 'hazy')
'it's my disorder' is the wordplay.
'disorder' indicates an anagram (I've seen 'diseased' mean this (I've seen this in other clues)).
'its'+'my'='itsmy'
'itsmy' is an anagram of 'MISTY'.
'that makes things so' is the link.
I am not very happy about this link. Some or all of it may belong to 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" .)