Tony,
You have got to be the most optimistic, trusting person I know if your words on this forum are anything remotely compared to your actions in life. I can't even imagine the amount of contstraint it would take for me after finding out something like that.
I do find it surprising yet soehow correct that you find relief now that you know the truth. It seems it wasn't your fault nearly as much as you make it out to be. At the same time, I don't know how compelled Lori is to rekindle the relationship ... as you very well know, it takes two to tango.
I hate to be pessimistic here, but if you do happen to get back together (which would be wonderful), I recommend that being the one and only second chance. Should this situation repeat itself, it's time to get out for everybody's sake. I've seen married couples that keep divorcing and getting back together again; it really messes with the kids' minds.
Good luck. I know you're going to pull through no matter what the outcome.