I didn't see your new post. I'm so sorry. Do you really want to be married into that family one day? Ugh.
I think he is seeing someone else, but it literally was a day later he changed his mind? It made no sense.
OR... he started dating someone else, she realized it was a very bad idea, and dumped him.
My ex-fiance said all the BS in the end that I was abusive and angry when he called off the wedding. He forgot to add in some details, which was he was never reliable (often one to five hours late), took it upon himself to blatantly flirt with other women in front of me, and cheated on me at least once if not twice. He wanted to look like the good guy because he knew deep in his heart that he was not so. If he threw me under the bus, oh well.
Ten years later, he was apologizing to me in a parking lot for his behavior (ran into each other). When he had broken up with me, my mind was filled with all these fantasy scenarios of how he would say he was sorry to me. What I never imagined was when the opportunity presented himself, I really didn't care. I was so indifferent I felt nothing. Well, no, that's not true, I was annoyed because he was making me run late and I needed to get back to my husband and son. I had moved on.
And you will too.