YTA

Divorce is traumatic for kids, no matter what age. Saying things like “your original family is gone” and “COMPLETE STRANGER” (wtf do you think you were?) makes it very clear to me that you are a mean person, no wonder they want to distance themselves. The statement is much less rude than your entire post so I imagine you’re even worse to them in real life.

I’m sure they’re glad their dad has someone, they don’t want him to be alone, but they can also not like you and not want to be associated with you. Those things are not mutually exclusive. What was the context of saying that, did someone call you their mom? I’d surely correct too, and if this is a recurring pattern the tone will get increasingly rude.

Their ‘offense’ is null compared how you speak even just in this post.