I went to the emergency room instead of trying to just last out a chest pain + allergic reaction at home like I have in the past.

I used the time travel technique from HPMOR. Blurb at the bottom.

Pro: Still alive

Con: Really hard to do in moments of crises; I was only able to do this after about 15 minutes of time spent driving home (and then I U-turned to go to the hospital).

Blurb:

He'd wished then to fall back just a few minutes in time and change something, anything before it was too late...

And then it had turned out to not be too late after all.

Wish granted.

You couldn't change history. But you could get it right to start with. Do something differently the first time around.