I'm sorry you are in such a difficult situation. Here are links to 4 articles, from PC's archives, that discuss various aspects of being in a relationship with a narcissist plus a link to 1 article that discusses FAQ's for partners of sex addicts & 1 that talks about leaving a sex addict. Hopefully within these articles you may find some insights that will be of benefit:

What Are the Signs that You're in a Relationship with a Narcissist?

11 Signs You're the Victim of Narcissistic Abuse

Narcissistic Abuse and the Symptoms of Narcissistic Abuse Syndrome

5 Ways to Know If His Love is "Real" or Narcissistic-Illusion

FAQs for Partners of Sex Addicts

https://blogs.psychcentral.com/sex-a...ked-questions/