I have encountered the now-infamous "Forever Mourning" bug in Skyrim. The "Forever Mourning" bug is encountered after completing "Blood's Honor" (where you kill the witches for their heads, for the lycanthropy cure), you return to Jarrvaskr to see the Silver Hand had attacked the area, and inside the building Kodlak is dead. You turn in the quest to Vilkas, but for whatever reason he doesn't give you the next quest in the line, "Purity of Revenge". Instead, he ends up going into "busy" mode (where you can't interact with him) and everybody is "forever mourning" the attack and the loss.
I haven't cleared Driftshade Sanctuary or completed the "Find Helm of Winterhold..." miscellaneous quest. What should I do?
I've heard that I should get the Helm without killing any enemies inside Driftshade (using Invisibility potions and such), then wait 32 in-game days, then return to Jorrvaskr. Is there another way? How can I get around this bug?
I am playing on the PS3.