Those who lack empathy don’t like it when what they’ve done is brought up again and again, while you work through the trauma they caused. They expect you to move on. Even IF they apologized they expect you to move on. They often get impatient and even angry if you continue to have feelings about the pain and betrayal they’ve put you through, the hurt they caused. They think you’re “still making a big deal” out of nothing.
Their response shows they lack empathy. They have a character flaw.
The reality is, they moved on the moment they traumatized you. And often they think there is nothing to move on from. Their ease of moving on exists because they lack of empathy and compassion. It’s not you who has a problem.
Don’t let them gaslight you into believing that what they did was not a big deal. You matter and your feelings matter so what they did IS a big deal.