So today I became a vampire lord again in order to enter the soul cairn to get the spell tomes there. Once this was done I went back to Aela to become a werewolf again, but to option for her to make me one isn't there. I'm pretty sure this is the only way to become a werewolf outside of the companions questline so if anyone knows a way to fix this I'd be grateful.

You can only become a WW twice. Once during the Companions, and the other when you ask Aela.

You can't get it a third time.

Hmmm...that svcks. Thanks anyway.