Dude, my first thought was to read you a riot act, but I'm guessing you've been over that a million times yourself already. You said all things happen for a reason, which I agree with; maybe the reason is to remind you to always take the necessary precautions in the future to keep something worse from happening.
..... and NEVER get a under a car when there is no one else around.
Sadly, I have no option. I live by myself, and none of my friends around here are into cars that much, with the exception of one guy two hours away who could get away maybe once every other month.
When I raise a car, I place a minimum of two jackstands, four if I can, and usually leave the jack in place as a backup. Then I heave on the bumper as hard as I can. BAsically I do everything I can to make it fall while I'm NOT underneath, before I crawl under.