Am im ungrateful

So i left school and am currently homeschooled (ever since last September )because my mom had a baby and needed to work. So moral of the story is that i have to watch the baby all the time( he's one). Even when she comes home i have to watch him. Like can i get a break. Call me ungrateful i dont care. When we get into arguments she always wants to call me ungrateful and how i dont do anything for her.Like you got me twisted im the only one helping her. All im asking for is a break every once and a while. Hes my kid bit hes not my kid.( i act lile hes mines but i didnt birth him. Am I wrong. (Im inly 15) Its like i dont have time to be a teen.