Seems like lots of people are getting various "crash on loading" issues that only appear after some point in the story. I have a similar issue to yours except that it hasn't prevented me from progressing in the story. I just can't load a save more than twice during one instance. Essentially every time I want to reload after screwing something up, I have to restart the game.
I've tried every damn suggestion I could find on the internet. Neither well-known or relatively obscure suggestions have been of any help.
Don't feel like this issue won't be addressed - I have to imagine that game crashes are pretty high priority on the bug-fix list for the devs (especially considering how many people are experiencing crashes of a similar sort). You're welcome to continue trying to get things to work but something is very clearly wrong with the game itself. Hopefully the next patch will sort some of this stuff out.
