I try to find a solution/make a plan for each thing I am worried or anxious about in order to lessen my anxiety.
Few examples...
Worried about gas station accessibility to easily exit. So I always plan my gas station stops by finding an appropriate station on Google maps satellite view beforehand.
Worried about trying to get to a certain destination before dark. So I always plan our driving days to be not more than 250 miles, because I know we start late and our rest stops are somewhat lengthy.
Worried about breaking down on the road (which has happened a couple times recently). So now as I drive I am constantly perusing the shoulder for potential space to pull over.
Not saying my worry and anxiety is all gone, but figuring out a way to deal with each separate thing has really helped me.