If I’m psychological kin (I have spiritual kintypes too, so I know it’s different) with a fictional species (specifically werewolves from teen wolf, and that specific type of werewolf), do I use fictionkin? Or am I just otherkin?

That’s a heck of a grey area, anon. I’d say if the type of werewolf you are follows the specific rules of werewolves from teen wolf, and you remember the ‘rules’ of that world being true, then I’d call you fictionkin. (as well as being otherkin too)