All I can say is, don't compromise your life because of fear. In other words, if it's in your blood to ride, it makes sense to ride.
You can maximize your opportunities, though. Sounds like you need some training on keeping your mind engaged while riding/racing and you need some training on throttle management. I could be wrong but what I would suggest is that you go to a racing school that teaches both things and also consider a sports psychologist. They can do wonders for you.
One of my friends puts a post-it note on the dash board of his bike with a note about what he's working on. Something like, "Look through the turn," or "Throttle control," or something like that. That way, it keeps reminding him and he doesn't get lost in the ride as we all have a tendency to do.
Optimizing your enjoyment means living longer and enjoying it more and sometimes that does require taking a step back and re-learning some skills that will make that possible.
Last but not least, I don't know how your girl is, but mine would be very saddened if she saw me give up something I love just because I was afraid to die on a bike and leave her behind. She obviously wants me to live life to the fullest and if I die doing something I love, what better way to go?
It's not a replacement by any stretch, however, I do have a decent life insurance policy and need to get a disability policy as well.
Just some thoughts, though. Not trying to tell you how to live your life but take it for what it's worth to you.
--Wag--