First of all, sorry you're hurting, break ups suck.
Second of all, please do not take a 'reality' show such as Polyamory: Married and Dating as a guidance manual for the 'right' way to do things. Remember these things are scripted and edited to within an inch of their lives, I saw some pretty unsavoury behaviours amongst the cast of that show and I am pretty sure other experienced Poly people did too. At the end of the day just because you saw their relationship continue, whilst yours did not, does not mean that you needed to have mimicked them for yours to have worked, the truth of the matter is, most relationships do not work out in the long term even with the best relationship skills and the best will in the world.
Added to that complex emotions and expectations and well it's not greatly surprising.
I hope you can all move on and hopefully rebuild a friendship with your ex.