Because sometimes you're lycan half is scary as balls.

I don't use the split personality trope for werewolves personally, but it is a good metaphor for a more primal reaction to events. As well, Pam kind of looks to her wolf like nature as something not herself. This can sometimes manifest in her dreams. She doesn't really understand that it's her brain realizing that it's part of her now while also giving form to her fears and concerns.