Just ranting. Nothing to really do with being pregnant

So my husband and I live with my dad. My husband had to file bankruptcy almost 3 years ago due to his ex wife. We tried to get a house but can't at the moment because of that. In November we will be able to get one. We live in the basement at my dad's and have a dog. We haven't been able to rent because of having a dog and my dad WON'T help me get a house. He told me about a month ago that if he buys that house I could rent from him for 800 a month. My sister rents a house from him for 500 a month that my dad built for her. That's the second house he built for her. A friend of ours might be possibly selling his house very soon and would work something out with us. Is it wrong of me to be bitter towards my dad because of how he treats my sister compared to me? Also I don't want to rent from him. He helps everyone except me. I haven't told him I'm expecting yet either because I'm afraid of what he will say. I so desperately want my own place but I don't want to pay 800 for rent when that could be a mortage if he would just help me.