As nouns the difference between feelings and bitterness
is that feelings is plural of lang=en while bitterness is the quality of having a bitter taste.
feelings
English
Noun
(head)
Anagrams
*
----
bitterness
English
Noun
the quality of having a bitter taste
the quality of feeling bitter; acrimony, resentment
Synonyms
* (quality of being bitter in taste) acerbicness, acridity, acridness
* (quality of feeling bitter) acrimony, gall, rancor/rancour, resentment