Feeling Guilty - Mother Says I Don't Care for Her

As-salamu alaykum, I moved abroad for my studies and live with my older brother. Recently our mother came to stay with us for a while. I used to be excited to spoil her and look after her, but lately I’ve been angry and stressed because of goals I missed and plans that fell through. I’ve been trying to cope by praying and reciting duas like Hasbuna Allah wa niʿmal wakeel and the dua of Yunus (A.S). At home I handle most of the household responsibilities - I pay the rent, buy groceries, clean - while my brother, who doesn’t have a job, does the cooking. My days are basically work, school, cleaning, repeat. When our mother is hungry she usually calls my brother. For the past three days I’ve felt drained from the moment I wake up until I sleep. I don’t have the energy to talk or smile and I notice I wear an angry expression. Today she said to me, “I took care of you when you were a baby; now that I am old and you are an adult you are not taking care of me.” That comment shocked me. I can’t always cook because I go straight to school after work, and I sometimes feel she could be more independent instead of watching TV most of the day and only getting up for prayer. I keep wondering: am I a bad daughter, a bad Muslim? I want to do right by her and by Allah. Any advice on how to balance my responsibilities, manage my low energy, and show care in ways that fit our situation would be really helpful. JazakAllahu khair.