@Played,
Don't be jealous of him or them. He's not real..and when he was with you, he acted in certain ways to sell you on a fantasy image that he wanted to portray.
Consider getting into some short-term counseling. In this sort of situation, it might help you make this transition.
Don't look to him for any validation, answers, explanations or apologies as there's no answers that will be satisfying nor will it be the truth.
As difficult as the task may be, move on with you life.
Consider that you've learned a valuable but expensive lesson. You're very fortunate that you've logged no more additional time with this sort of phoniness and insincerity.
Understand that he'll never be happy with anyone as he's congenital liar and a narcissist. Block any exposure to him on social media, phone and path-crossing in your geographical area. No contact again - ever.