So I was playing one of my characters last night and everything was going fine. I was doing the mission for Caius in which he wants you to investigate the Sixth House base near Gnaar Mok and I was making progress in the area when I got one shotted by a Winged Twilight.

Unfortunately my last saved fiile was from a while back and when I went back to Casius to get the ball rerolling he just says that I already have Corpurus disease and need to go to Tel Fyr. The problem is that the NPCs in Tel Fyr all have their normal dialogue and not only that but the citizens of Gnaar Mok won't even talk about Gnaar Mok but when I search through the base the Dagoth that's actually supposed to give me corpurus isn't even showing up in there. I tried healing myself of normal blight too but that didn't fix anything.

I play on xbox so I can't just advance the quest stage but what I would like to know is can I just go kill Vivec now for the Wraithguard he has and do the back route the game provides or is my main quest screwed on this character?