Physically? Probably the time I was hitchhiking on the Mass Pike at night, saw a truck coming up way too close to the breakdown lane line, dove out of the way, rolled down an embankment, and slammed into a chainlink fence. Hurt like hell but nothing was broken so I climbed back up the bank, walked the two miles to the nearest rest area, and caught a ride with a trucker to my destination.
Emotionally? April 8, 1998. I came home from class to find my fiancée waiting for me...she broke up with me and I couldn't move out of the apartment we shared until the end of the month. The closest I've ever come to committing a homicide while sober came when she brought her new boyfriend home and made out with him in the spare bedroom while I was home. This led to me hooking up with a female friend about a week and a half later, ruining the friendship in the process, and screwing her on the bed I used to share with that ex-fiancée while she was home as a revenge fuck. Things calmed down after I moved out (I didn't have to see her, she didn't have to see me), but for a 20-year-old in his first real serious adult relationship, it was a roller-coaster ride for the ages.