Ur not over dramatic hun. I know how u feel cuz i have toxic brother too and he keeps on making hurtful commets now and then by the time i was actually getting depressed due to every day humiliation but idk one day i started giving back to him. i stopped making myself feel that I'm inferior then him when he mock about my flaws i do the same. i never start anything unless he does & i completely avoid his existence i made very clear to him that he has no part in my life. i pay no attention. not even considering him as brother too. u should do that. stop being hurt and stand up. make him clear that he don't matter