Is it normal for my father to stop providing?

I just recently turned 18 and I am still living with my father. (I have no mother.) I am leaving for University soon but for the mean time I still live here with him. He does not pay a mortgage or any significant bills besides his own transportation costs because we live with my cousins and they pay the bills. He doesn't have a steady job but he has his own small business that he occasionally makes money from. Recently my father has stopped buying groceries (which is his only real household responsibility) and because of this I have been starving and having to live off of some old oatmeal in the pantry. There are no fruits or vegetables in the house. I asked him to buy groceries but he said that I am an adult and I can go get my own groceries. I have no job and no car and I know that he still considers me his dependent. He also said the other day that he doesn't want to give me rides anywhere anymore because "adults find their own rides." I have a feeling that my father is becoming insecure about my newly acquired freedoms and responsibilities that come with being and adult and is using those as a justification for abandoning his fatherly duty and comforting his own insecurities. What would be the proper way to address this problem with him?