Please help me. What should I do???!?

So Just two days ago my cousins flew in from Florida with my aunt. Yesterday all of us were on good terms. So mind you o have not slept good for the past 6 days. But today is my cousins birthday. And I bought her a pair of jeans that she wanted at first. They were 30$ and I don't have much money to begin with. She opened my present and just put them back in the box. So later on I told her will u please try these one. She said yelling at me no there ugly and I hate them. So I sat by the door so she couldnt get out and said you need to stop yelling at me. She started balling her eyes out and me and my friend went to the park just to get away. Wen we came back her mom came in and said don't ever do it again blah blah blah. And I agreed. So ever since then they have not talked to me. They are ignoring me. Callig me a snob. When I apologized. And I said we can take the jeans back. But no. So she started yelling at me again saying how mean I was. So my mom came into my room and asked me what is going on I said I'm tired of her being a brat. And I thought I said. It quietly but my aunt heard me. And now my aunt says she wants to change the plain tickets and leave tomorrow. I have know idea what to do. My aunt won't even let me talk to her to say sorry. But also I told her I'm running on fumes so don't get me started because I won't be saying nice things. Of course I want them to stay but I have no idea what to do. I can't even sleep.