Anticholinergic poisoning is a terrible way to die. You can look up the symptoms online. There are antidotes -- acetylcholinesterase inhibitors, such as physostigmine.
Edit: The tropane alkaloids from the deadly nightshade (Atropa belladonna), jimsonweed (Datura stramonium) or henbane (Hyoscyamus niger) are powerful deliriants -- they will force you into a state of delirium and insanity while killing you. Some people take Datura as a deliriant drug to trip on, many times to disastrous outcomes.