How do I deal with betrayal

Someone I trusted just turned out to be a pathological liar narcissist
Who used me just as an ornament
I loved them so dearly but to them I was nothing but just a toy
I have forgiven them cause I realise that they had some problems in their head and I don’t need to hate them as hate is just as binding as love.
But I got played and I have to live with the fact that the person I would’ve died for betrayed me knowing I was already going through so much.
My only problem is I ruminate on it all and sometimes feel like I would never have those parts of me again. I feel like I would never be able to give out my heart to someone like that.