Emily,

I posted an almost exact thread the other day. I'm a guy 5'8" 185 lbs.
I have the precise same discomfort. It's a mystery to me why many others don't encounter this. I currently have mine backwards; but this is not going to be fun if hit in rear.

I will also look into the Accord headrest idea. My first idea was to have a good upholsterer reconfigure the foam in the rest to be about 2 inches thinner and then re-stitch the cover ( the hard part of the job). Don't yet know the cost of this.
Good luck, Let me know how your solutions go,
Jim