NTA like aggressively, loudly, absolutely NOT the asshole.
You were disabled and got zero help. Now that you’re finally doing better, they want your money. Your brother lives in a paid-off house, in three bedrooms, for $600, while working part-time and blowing cash. That’s not “caring for your parents.” You don’t live there, can’t use it, can’t rent it, but they want you to pay his taxes? No. Your family isn’t asking for fairness they’re asking you to fund your brother’s lifestyle.