Discouraging situations, and discouraging comments, leave you feeling discouraged. It is the opposite of 'encouraging'.
'Discouraging' doesn't have anything to do with 'courage' in the sense of bravery. If something is discouraging, you feel less positive, confident or optimistic about it.
'Couraging' is a nonsense word. It doesn't exist. Nor does 'uncourageous'.