Let it go, move on and build. You can't fix it or do anything about it, all it will do is tear you down. Work on today and leave the past where it is. Are you looking for some kind of remorse or penance. Remember, he might not see his mistake the same as you do. Even if he did, will he ever be able to satisfy your never ending price for his guilt. It's a loosing struggle.
Capitalize on his desire and excitement to build a future. Remember excitement generates more excitement. Only negative forces want us to focus on the past. I have to focus on this as you do. For me this is the second time through this kind of mess. However, this time I have and understand DBing and of course you guys out there.