How should I deal w/ schizophrenic stepmom and stressed dad?

Hi. My dad married my stepmom a couple years after I was born. She seemed sane then, until I moved in during 2nd grade. Then she was totally psychotic. My dad suggested to me tonight that maybe she is schizophrenic. I researched it and it fit her profile exceptionally well. Then there's him. He's stressed all the time about finances and her b/c she is totally insane and agitated with me ALL the time. (Honestly, I'm a good kid.) We can't afford a psychiatrist for her and I just want my dad to be happy. I hate my stepmom. That's a nasty word, but it's true. She's horrible to me, and to him. But we can't do anything about it. My dad is always nostalgic about his childhood and his father and how his uncle took all the money when a family member died leaving them with nothing. He always talks about money. How should I address this issue with my dad? If I could give him a hundred thousand dollars, everything might be alright. Money doesn't buy happiness, but it sure could help. And stepmom?