Don't you just love when those old high school flames flare up again? It happens so often, it's a cliche.
So sorry for your situation. You have found the right place. There are many posters here who have a great deal of wisdom and insight to offer.
I think words like "true love and soulmate" hurt much worse than if he'd met some chic in a bar and had a one night stand. Just my opinion...but I've heard similar words and I can still hear his voice saying them over and over and over...