Dated a Narcissist

A couple of years ago I dated what I think was a narcissist, I mean, I don’t have this ptsd for nothing...

I think it really caused me a lot of trauma when he dropped his mask and showed me who he really was and completely changed how he treated and acted towards me overnight. It was like he just started hating me out of nowhere and I was just a body breathing air to him.

Now I always have this extreme fear that I’ll date someone else like that again and that everyone is the same. I know I won’t put up with it again in future and will recognise it if the flags pop up and I know not everyone is like this but I still have this deep fear gnawing at me. I dated someone who also flipped in behaviour suddenly towards me a year ago and it almost broke me. Does anyone else have fears like this?? Like whoever they date might not be genuine and are just wearing a mask? This sounds so crazy, I’m aware. But I’m wondering if other people that have been through this think like this too.