a massive overdose /could/ kill you, but i think unless you already have a shot liver, it's doubtful it will work. if it does, it's a long and drawn-out death...
with my own experience, my liver only really somewhat fucked out once, and that was from a chronic od event quite a few years. even than, my liver made an almost 100% recovery. sometimes aches after a big booze bender, and it always aches when i feel sickly or vomit...
imo, panadol is a great self-harm option if you want the medical attention n shit, but to ctb with it is meh and inefficient...