dis ‧ heart ‧ en ‧ ing /dɪsˈhɑːtn-ɪŋ $ -ɑːr-/ BrE AmE adjective
[ Word Family: adjective : heartened ≠ ↑ disheartened , ↑ heartening ≠ ↑ disheartening , ↑ heartless , ↑ hearty ; noun : ↑ heart , ↑ heartlessness , ↑ heartiness ; adverb : ↑ heartily , ↑ heartlessly , ↑ hearteningly ≠ ↑ dishearteningly ; verb : ↑ hearten ≠ ↑ dishearten ]
making you lose hope and determination
it is disheartening to hear/see etc something
It’s disheartening to see what little progress has been made.
—dishearteningly adverb