Uncomfortable, unwell but relaxing (3,2,4)
I believe the answer is:
ill at ease
'uncomfortable' is the definition.
(being ill at ease is being uncomfortable or uneasy)
'unwell but relaxing' is the wordplay.
'unwell' becomes 'i'll' (similar in meaning).
'but relaxing' becomes 'atease' (I've seen this in another clue. I am not sure about the 'but' bit.).
'ill'+'atease'='ILL-AT-EASE'
Can you help me to learn more?
(Other definitions for ill at ease that I've seen before include "wound up" , "Unable to relax" , "Elite, alas? (Anag)" , "Nervous, uncomfortable" , "Uncomfortable with a situation" .)