How to tell someone you think they’re a narcissist?

I keep seeing all these posts on ***, Tik Tok about traits of narcissistic people. Almost all of which I think apply to my companion.

Our relationship has been strained as of late and I believe a lot of it has to do with these traits. I’m not saying I'm innocent of any wrong doing but I believe I’m reasonable and easy going enough to try and keep the peace when needed.

I will stand up for myself when needed and I am human and have feelings too so sometimes things get to me and I speak out. It’s at these times when I feel these traits are really prevalent. No matter what I try and say I am the bad person and the issues are all mine (so it seems from how I feel from what she says). I believe this is what is called gaslighting?

If I can’t salvage our relationship I want to bring this up not for my own peace of mind and closure but also for her to maybe realize that she is also part of the problem so that if she ever gets into another relationship that she will keep herself accountable.

I am very certain if I tell her what I think she will not take it well and say that I am just being spiteful and hurtful putting us in this continuous cycle that is breaking us apart.

I truly care for her and our relationship but I have my own mental health challenges that I need to work on. I don’t think I can continue on emotionally if I can’t feel heard and understood.