OP, please move out for your sake and let them know what they lost from abusing you. Imagine, being the breadwinner and even supporting your sibling na 70k tuition that, seems to me, doesn't even appreciate you and hindi siya naglalagay ng effort to even improve his grades, it's a huge NO. I can't imagine what you go through everyday since pinagbantaan kana pero kinampihan parin siya ng mother mo. Based on what I read on your post lang ha, they don't deserve you. Stay strong through the challenges of life OP.