Antonyms for the phrase "am pleased by" include synonyms such as "am displeased by," "am saddened by," and "am disappointed by." These opposing words express negative emotions and feelings towards something that did not meet one's expectations or standards. Other antonyms for "am pleased by" might include "am indifferent to," "am frustrated by," and "am annoyed by." Broadening the scope, the antonyms could simply be "am unhappy with" or "am dissatisfied with," reflecting disappointment with a situation or outcome. In summary, antonyms for "am pleased by" include words or phrases that capture the opposite emotions and sensations from those that might arise when something is pleasing.