Assalamu alaykum, I'm emotionally exhausted and need guidance

Assalamu alaykum brothers and sisters, I don't know how to deal with this anymore, it's been going on too long and I feel I'm failing. My father is someone who prays and fasts, but his behaviour hurts everyone at home. I'm scared for him and for my family, so most of the time I freeze and do nothing. My dear mother cares for my fully disabled brother, yet he treats her like a servant and shows her no mercy. For years I thought studying hard and getting a good job would fix our problems. I spent almost five years working as a student and then two years after graduation just trying to get ahead. I had a student job that covered my expenses and often I skipped meals to save and help at home. I drank caffeine all the time because it was free at work, and I'd come home late and exhausted-instant noodles became my go-to so I could study more. I was hopeful and thought it was only a matter of time before things improved: that my father would stop complaining, my mother could rest and focus on her Quran. Instead, it's gotten worse. After graduation I tried different things: 1) I bought groceries, paid for gifts, gave money to my mum since she doesn’t work and my father never gave her even a small amount monthly. I took my mum out and bought clothes. Result: No gratitude, only insults and backbiting. He complained about money within my earshot and later accused me of trying to break up the family. 2) We stopped going out and I covered more expenses, including my brother's school fees so he could finish his final year. Result: No change. 3) I used most of my savings to pay a fine he owed for unpaid taxes and helped another brother start a small business with what was left. My mum also contributed all she had. Result: Still no improvement. 4) Now I give them each a portion of my pay, save the rest, and rarely spend on myself because he resents it. My brother who doesn’t earn much contributes as he can. Result: He smokes less around me, but now expects me to always pay for groceries and anything else. It causes constant fights and I end up spending a lot so my mother won't have to. I feel stuck. I’ve been working for two years post-grad alongside the years I worked as a student. Colleagues who started after me are already further ahead, cousins are traveling, friends are getting help to move out or buy cars. Meanwhile my father keeps complaining about how much I give and demands more. He even suggested I remove my hijab and look for work abroad, or take another job here-I already work for a multinational that pays well and raises should come with time. Last week he even asked me to cozy up to my managers so my brother could get a job. That request hurt me the most. I can't rely on my brothers to change things later. One is struggling financially, and the other is like my father or worse. My youngest refuses to study or work, keeps asking my mother for money, and has anger problems. He caused trouble with neighbours that ended in police visits twice; the neighbours acted because of his repeated bullying and spiteful behaviour, which grew because my parents often sided with him. Even my mother defends him because she loves him beyond reason. Small daily things fall on us: for example, my father insists on fresh bread from the bakery every morning but neither he nor my brothers will go get it, so my mother or I do it no matter the weather. If we don't, he accuses my mother of not making him breakfast. My father isn't poor, just extremely stingy and harsh. He avoids spending even on himself. He has a car and a motorcycle but often walks to save money. If he were poor but kind, I would gladly help-it's his coldness and cruelty that make it so painful. Over the years I’ve become bitter. I don't give from a sincere heart anymore and I hate who I'm becoming. I'm angry at my brothers, especially the youngest who always defends our father. I wish we had someone to stand up for us, but it seems it has to start with us. I know I've made mistakes and perhaps contributed to this situation, but I don't know how to break free. Please advise me on practical steps I can take-emotionally, financially, and within Islamic boundaries-to protect my mother and improve our lives. If patience is the only solution, please make du'aa for sabr for us and for guidance. Jazakum Allahu khairan.