Has anyone ever dated a narcissist and or sociopath?

I have... it's been about six months + with no contact but I still find myself wanting to stalk his social media. It's awful. He has just found a new target, and has impregnated her and asked for her hand in marriage within a month. I'm scared for her because I know the pattern. The lies, gaslighting, manipulation, all just to get their resources. Once they're through, they're through with you and you're discarded, alone, miserable, and emotionally very wounded. I can't even begin to tell you how difficult recovery is from dating a narcissist or sociopath. Does anyone have any stories they'd like to share? Thank you in advance.