If you feel able to ignore and block him, then do so. I think it's awful that he's kept you on back burner and almost stringing you along. Why not just say that he's met someone else? Why not just say that he did not want to be in a relationship with OP? I think it shows the deficiency in his character. I'm not talking about age gaps etc, because if he'd met a lady in her 50's, but still told OP the same stuff, I'd think the same.
If he really does have financial problems though, I'd be glad that I'd escaped that one and I'd pity the new woman (unless she has a bank balance like Elon Musk's).
I understand why you're upset. Try and look after yourself though. Speak to friends and family for a bit of support and start with little/often for eating and self care. Give yourself time x
PS FWIW....when OW came out the woodwork, XH told me that she was the best thing since sliced bread, they were soul mates blah blah blah, she understood him better than anyone else. I knew OW (she was a friend), and I knew some of her history (behaviour wise). Broke my heart but also, he was her problem, and I just sat back and waited for the shit to hit the fan with them (I knew it would). Four months after me finding out about her, they broke up in a total blaze of glory. So don't pay too much mind to all the shiny new crap he posts (and seriously, just block him on everything!!) - the only reason I bloody couldn't block and ignore was because I was filing for divorce and we shared a DC. Even if your ex and his new partner don't split, just leave them to it x