Silent crying

A family member made me accompany her to get treatment for her diabetic swollen foot claiming it was my fault for forgetting to buy her medicine last week. Feeling guilty I went along. You know what she did? I had told her specifically that I am on a tight deadline and had applications to finish. First she went around the damn supermarket 6 times, why, claiming her grocery got finished but she went spent about 20 minutes staring at the damn shampoo aisle. Then she wanted to buy ice creams, cookies, food, food,food, argghhhh. Then finally dragging me to the pharmacy, she spent a minute getting her medicine and about 30 minutes asking about hair dye and shampoo. When I finally found my tongue telling her I want to leaving, she started screaming and shouting at me, saying it was my fault her feet got swollen on Christmas day. Then when I went home, she spent 3 hours verbally abusing me while I made weak attempt to do my essay. Why does this keep happening to me? I can't take it. Feel like crying. I have so many essays to finish and people are so inconsiderate. Nobody gets it. Just want to give up.