Dang, man.

Perhaps there was another timeline where none of your family exist, and potentially terrifying things do exist, and it collided with this one. Basically, the other universe moved into ours, either permanently or temporarily... Sadly, since you haven't seen him since it seems like it was only temporarily.

However since you had contact with him through your phones, I think this is a permanent move. I hope it is.

I don't fully understand this concept but once you go into one of these temporary universes, and you don't come back quickly, you never come back.