For my other character I have fully unlocked the werewolf perk tree. I can't find a way to access my new roars though. I noticed they are called totems, so do you have to collect them like the other totems with Aela?

As far as I know, yup!

I've heard you do have to find the totems to activate them. You also can only have one active at a time, and have to go back to the totems' location to swap out the powers.

Stupid design decision if you ask me, especially since the Vampire Lords can toggle their powers at will.

I know, we're just too good!

You need to start the Companions quest line, then start doing side jobs for Aela. Every so often she will ask you to join her in the search for a totem, there's 3 in total, each are placed in the Underforge. Once you have all three you can swap them out by revisiting the Underforge and praying at what ever totem you want.

No new totems. Getting the perks upgrades the shouts you get from the original totems.