I'll take your word for it, I hope I never have to find out. Sounds like a horrible way to go.
Not really. One of my friends got a near lethal dose. In a matter of a few seconds his vision tunneled down to nothing and he blacked out. No pain, very quick.
He woke up a few minutes later with no lasting effects - typical of cyanide, if it doesn't kill you outright, it usually doesn't permanently damage you.
In my case, I got just enough to smell, from residue on my gloves as I pushed up my glasses with the back of my wrist.