So I'm trying to complete the "Season Unending" quest in the main storyline. I decided that since I was going to Windhelm, I might as well do the "Joining the Stormcloaks" quest too... So I went and killed the Ice Wraith and now that I've returned, Ulfric wants me to talk to Galmar, and I can't even talk to him. He's saying that he's amazed that I got Ulfric to talk to the Empire and that it's a waste of time, bla bla bla... Anyway, looking for help here, I can't talk to Galmar at all. Everytime I press E, he just repeats "I don't know how you convinced Ulfric to talk to the Empire. Worse than a waste of time if you ask me."

He just says it over and over again. I'm thoroughly confused and rather frustrated.

Thanks.