Breaking up with a narcissits.
I’m confused, why is that different from breaking of with a non-narcissistic person?
Because of the effect of the psychological abuse experienced during the relationship.
You will have been lied to, cheated on, insulted, criticised, demeaned, experienced narcissistic rages which make Eastenders look like rational conversations which can last many hours /days, spent much of your life living in fear because you never know where or when the next rage/beating is coming from or what will trigger it.
By the time you get out you may well have lost your self esteem, self confidence, have pretty severe depression and anxiety, not be sleeping, have complex PTSD , Stockholm syndrome, paranoid schizophrenia (rarely) and be completely unable to trust anyone for a long time.