The phrase "feel ashamed" can be effectively substituted with various synonyms depending on the context and intensity of the situation. For instance, one could use "feel embarrassed," "feel guilty," or "feel humiliated" to portray a sense of discomfort or self-consciousness that may result from an action or circumstance. Other synonyms include "feel mortified," "feel chagrined," and "feel contrite" which denote a deeper level of regret, remorse, or penitence. Additionally, one could use "feel sheepish," "feel awkward," or "feel uncomfortable" to convey a milder form of shame or inferiority. Regardless of the synonym used, it is essential to choose an appropriate word that accurately captures one's emotions and communicates them effectively.