Scared of the motorway

That's quite a long drive. Can you split the journey and stay over on the way...Premier Inn. Then each day you only have a 3 hour drive with some breaks.
I find it better to drive on my own in those sort of circumstances. Then if I take the wrong exit or whatever I don't have to explain myself. I haven't got satnav but it you have have a practice as suggested above. Otherwise plan your route. Write down all the exit numbers on a couple of sheets of paper in large letters/numbers. Have all your emergency phone numbers to hand. Plenty of water and snacks. And food luck....you can do it.

Please don’t be embarrassed You are very wise to acknowledge that you’re nervous. They are dangerous roads.
If you feel as nervous as you sound motorways aren’t the safest roads for you and other drivers.
Is there a motoway near you that you could use ( with your husband) and get some confidence.

I live in a county with no motorways and very few dual carriageways. In the ten years I've lived here I've really lost my confidence on motorways. When I visit my family 200 miles away I have to use two. I always leave very early in the morning (about 4 am) to avoid traffic. I also use my sat nav, even though I know exactly where I'm going, because it tells me to keep right or left when other roads merge or diverge. I'm really embarrassed about this and it makes me feel absolutely pathetic.

Just remember that if you do end up taking a wrong exit, that you can carry on then backtrack.

Do you have a cell phone with google maps? Get familiar with using their directions; it's brilliant. Try it a few times in your local town; input the grocery store or location across town to practice.