Ladies I need to vent 😔 advice?

Jennifer
So I turn 16 on the 21st I moved in with my uncle and aunt in Colorado about 2 years ago because my parents where alcoholics and very abussive. My aunt and uncle have two girls who are 2 and 4 and they can be a real handful. During the summer I watch them everyday while they work. I don't really have time with friends and do a lot around a the house. I also feel like my aunt and i are the ones who are so involved with the housework and my little cousins and my uncle is never in the picture. I talked to him about it last night and he said he's tired and when he gets home from work can not handle the kids and that their too much for him so he goes down stairs on his computer and we don't see him until dinner and then back downstairs. When he is with them he gets so frustrated. The girls need their father. He said that when he was my age he had responsibilies, but I watch his kids all day everyday and he barley spends two seconds with them a day. I feel like a single housewife of 2 at 15 years old. 😔  he's home for lunch and just goes down stairs on his computer while his little girls are upstairs yelling DADDY DADDY and then he gets frustrated. He got so mad at me the other day for not doing the dishes that my aunt and I do everyday that he never does, and when I asked if he could do them because I was at an interview at the time he got mad and made me do them when I got home. He said If I can't handle those responsibilities I should just leave. I have no problem working and doing my responsibilities but it's when I'm doing his responsibilities and have no time to take care of myself is when I have a problem. I love my uncle and love my cousins but I refuse to take over his responsibilities as a father and do things that he should be doing. It's hard to balance taking care of myself and taking care of my cousins and the house when he isn't doing them. All of his has just become a source of anxiety for me. 😔 I don't know what to do. Advice?Â