Nanny that's driven insane?

I found a book at the dollar store years ago but I have completely forgotten the name. From what I remember, a college age girl moves to San Francisco for college and becomes a live-in nanny for a wealthier family who has a young son. The mom kinda ignores her kid and I think the dad is nice but is gone a lot for work? I know the main character starts to get gaslighted and locked in her room and she references The Yellow Wallpaper a lot and I think she gets a boyfriend possibly that helps her escape?