Narcissists Lie - "Your not trusting the narcissist will be turned around to paint the picture of YOU being insecure. You will be accused of being “jealous” / insecure / damaged / broken. All things you’re not – but things the narcissist is. You will begin to believe that you are insecure for not trusting them. You in turn, stop trusting yourself and your own perceptions and rely on someone who is lying to you." by tabby7cat
People need to let go of this insecurity and live their life for themselves, no one else! Focus on and love the things that matter the most in life. Move on from the hurt and lean not on your own understanding!