Assertiveness is very much a question of a right relationship with the self.
We make ourselves suffer when we (1) put our ‘self’ before others, (2) fear loss to that invented ‘self’, and (3) pin the blame on someone else.
When we project, we push the responsibility for our being onto someone else. We do it to avoid suffering. But, in fact, we end up losing touch with reality, and creating more suffering.