Evil stepmom!!! what do I do to help my dad?

so 4 years ago my dad had just divorced my mom then he met my stepmom, paula. Things were steady at the beginning, but now things are a mive earthquake. For 3 years now my dad has been living through hell with her. The reason this has happened was because of her dog. her dog, Buffy, who is a pikapoo and little white dog, is a really nice playfull dog, but Paula is crazy about Buffy! She acts as if Buffy is more valuable then her own husband. And she has erational fears like the dark, being down in basements, and getting dirty (she doesn't let us wear shoes in the house) and when Buffy eats a tiny piece of human food. She hates me too and thinks I'm a spoiled stupid brat which I don't think is entirely true. But most of all she doesn't help my dad in any way because their always argueing about the dog or something. I hate it. What can I do to help my dad? please help me.