That's too bad. No autosave you can load from before it started? I love KC:D; it's one of very few story-based games that I was motivated to play through more than once. I had a quick look, but I couldn't find any mods that let you pause that section and come back to it later.
I really enjoyed Theresa's DLC, but it can be an unwelcome change of pace if you're not ready for it. There's certainly no shortage of people that have had this issue, but it looks like the only fix is to power through it or load an earlier save. You do get a nice Skalitz shield from Theresa when you finish it, at least.
I really appreciate this take. It's good-hearted and makes good sense. I'll try to remember it going forward, when cynicism overwhelms.