noun. The state or condition of being unassertive.

noun. diffidence about self promotion

"Researchers have found that the more we identify with what are considered negative “feminine” traits, like passivity, dependence, and unassertiveness, the more likely we are to suffer from body image problems and disordered eating, regardless of our sexual orientation or gender identity.18"

diffidence  self-distrust  self-doubt  

assertiveness