Annoyed with 'boss'

So I nanny, I'm also pregnant with my first baby. The woman i nanny for is disrespectful every single day. They give their daughter to me in the mornings, when she comes she is soaked in her own pee, wide awake, cranky, and she smells like she hasn't had a bath in a week. They tell me that they will be at my house by 5AM, so I wake up early to get everything set out and they come at 6AM. They pull at my cats fur when they come over(yes the parents), they don't give a crap for my appointments, or my husbands appointments, they do not let me leave the house while I have their daughter(6AM-5:30PM), they fully expect me to do their daughters laundry. I watch her in my own home, I use all of MY stuff for their daughter(the only thing they give me is diapers and wipes). I'm also only getting paid $2.36 an hour!!! I am ANGRY because they expect me to raise their child while they disrespect everything I have, they think I'm a stupid 20 year old who doesn't realize they are scamming me. My household income is $23,000 a year(including my husband) while the people I babysit for make a little over $35,000 a year. I am only working because I would like to go back to my home town for Christmas along with put money away for my baby! But I am so tired of being disrespected and no matter what I do or say, they don't give a crap! I am too nice to say no to someone because I understand they need help while they work, but there is day cares all over this town. When I tell my 'boss' that I have an appointment she tells me that I need to make it quick because she didn't want to watch her daughter long! Her daughter is 9 months old & still doesn't crawl. When her parents come to get her, they lay her in the middle of my living room and say 'crawl bitch' they also hold her upside down by her leg for fun! This is a DISGUSTING family!! And I have no idea what to do about it!