For various reasons, there's a good chance I'm going to need to drive overseas (in a country I have visited several times before).
It's a technically easy trip, mostly toll roads and highways. I'll have sat nav, phone (with local people expecting me at the other end) and I am a competent driver and have travelled by car round lots of it before - just never driven long distance there alone. Women are generally safe there, but you wouldn't want to break down at night. Also the traffic police can be a little corrupt if they stop foreigners.
I'm doing a similar length/style journey in the UK shortly (to somewhere I have never been before) and I am not batting an eyelid. So why I am so inexplicably nervous about this one? There is no easy alternative way of getting to my destination.
(I'm sure if/when I do it, I'll look back and wonder what I was fussing over, but....)
I know how you feel but it sounds like it'll be fairly easy drive at the destination.
I travel to my home country every summer and pic a hire car at the arrivals. I've learned to drive here in the UK and had lived away 10 years before I learned to drive so it is like driving abroad for me even though it is my home country. And it is right hand drive there too.
At first the nerves were horrendous and it didn't help that I had two small children with me too. But that knot in the stomach didn't last very long and the driving started to feel enjoyable.
I don't feel nervous any longer but it took about four trips until I didn't think about the drive ahead at all.
By way of update, I have done the dreaded journey.
It got complicated by a necessary errand bing added on, and I got lost several times during that (sat nav map had junctions and turnings v close together so I either went early or missed it and had to reroute). But I made the main journey with no problems at all.
I also found this very very nifty site, where you can plug in your start and end points and it basically does an electronic flip book of the google streetview images for you!