When you say a highway, is it really a highway, or just a busy, fast 2 lane road? I mean, you aren't allowed to ride on highways here. Why do you have to ride on these kinds of roads? Is it to get places, or are you just out for a ride?
I would never purposely ride on a highway, unless there was no other option.
On our recent tour, we were on some very busy 2 lane roads in upstate NY. Lots of huge semi trucks. But there was a wide shoulder; despite that, the noise was bothersome and the wind from the trucks nearly blew me off of the road.
I just let the stupid comments roll off of my shoulders. They are ignorant. Don't let it bother you... if you have the right to be there, well, tough luck to them. It sounds like riding under the same conditions as your daughter's accident is triggering the fear again. That's why you are crying. It's still there...