It's over
This companions questline is absurd. I don't know who decided on this balancing but there's such a large difficulty spike after you become a werewolf that it's impossible to complete until you're level 60+ with daedric weapons and armor.
The tomb of Ysgramor is guarded by a pack of at least 7 level 75 undead werewolves with 300 hp, and as soon as you go inside it's filled with level 50 nordic ghosts with 500 hp and a shit load of armor. I can't get past them.

and I need to find a way to cure my lycanthropy asap.