Ok....some people may think me terribly insensitive, but based on your description of events, your actions sound more than a little irresponsible to me. Don't get me wrong...I'm glad the turtle is fine. And if I were to happen on a pokey critter sauntering across an empty road, I would not hesitate to stop and help it across...or move a snake that stopped to soak up the warmth from the asphalt.
However, there is a definite line, I believe, between helping an animal, and putting human lives in danger. If I'm traveling down a highway at a high rate of speed and a small animal is suddenly in my way, I am not going to swerve to miss it and risk flipping my car in the process. If I see a small animal such as a turtle on a busy road, I am sorry, but that turtle's life is not worth risking the life of my loved ones or the lives of others on the road.
I have a feeling you would have forgotten all about that turtle if your fiance had been hit by a car. Or if your actions caused one car to swerve into another, causing strangers to get hurt.
Maybe I'm reading more into this than there is...but I do sometimes get frustrated when it seems like human lives are not worth spit while a turtle's life is worth everything.
EDIT: And you judge all the other drivers on the road as "jerks" as they whiz past you, but chances are they never even saw the turtle...just two people out on the road for no good reason they can see. Just something to consider...