BTW I also hate doing bridges, either as a driver or passenger, but what I do is just keep my eyes fixed forward.
Sort of like wearing invisible blinders.
I do not think your fears are ridiculous, I have gotten use to all this stuff over time and now I drive so much I do not get upset, just in traffic jams or around aggressive drivers.
Being the driver I feel better, but when I am a passenger (especially the way my husband drives) I get uptight.
I think doing this gradually will be a big heelp to you

Lots of luck,

DE

In giving advice seek to help, not please your friend
SOLON