actually its fairly hard to die from d-amphetamine... need to take a single dose much higher than 400mg, and odds are you'll just start having a seizure and be sent to the ER before you can die...
the only time i ever honestly felt close to death was being on methadone, clonazepam, and drinking alcohol at the same time. I went down to like 3 breathes per minute, and had to force myself to stay awake... but its hard to force yourself to stay awake when you cant even stand up