benzos aren't going to kill you unless you take MASSIVE doses or mix them with opiates or othr CNS depressants. You will just blackout and act like an idiot or pass out if you take too much.
Drugs affect everyone differently, only you know how it affected you in the past. 4mg isn't dangerous except that you might black out and do something you wouldn't otherwise or you may just pass out.... which isn't really something to worry about, but if you want to stay awake and enjoy it, then 4mg may be too much.