I have so many, it creates ill-feeling (9)
I believe the answer is:
animosity
'feeling' is the definition.
(animosity is a kind of feeling)
'i have so many it creates' is the wordplay.
'have' means one lot of letters go next to another.
'creates' indicates anagramming the letters.
'i'+'so'+'many'+'it'='isomanyit'
'isomanyit' is an anagram of 'ANIMOSITY'.
'ill' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for animosity that I've seen before include "Ill-will" , "Hate" , "Maoist yin generates spirit of hostility" , "Hatred" , "A spirit of hostility, rancour" .)