Oh dear - orange juice, mashed potato and ice cream are some of the carbiest foods - and I used to love all of them.

If you have a look at the dietdoctor.com website there are ideas and recipes there for low carb foods and meals. There is also lots of information on this website and forum that can help give you ideas of what sort of foods/meals he ought to think about eating. Without knowing his preferences it would be difficult for us to make recommendations - also you will need to get on-side whoever does the cooking for him.
It would help if he tested just before eating and then an hour after, then two hours after - just to see how what he is eating is really affecting him. I must admit that it was seeing the results when I started regular testing that shocked me so much that I decided, whatever it took, I needed to control my diabetes.
I've not heard of brief episodes of blurred vision - mine came on slowly during a one day long written exam I had to attend - by the end of the day I could hardly see and it stayed that way - and maybe got a little worse when I was tired. When I finally lowered my BG with eating very few carbs my vision slowly stopped being blurry and finally cleared. It actually is one of the first warning signs for me that my BG is elevated.
Oh being emotional can definitely affect your blood glucose - as can having any kind of illness, even something as minor as a cold can make it go up. Your BG is basically your barometer to how your body is coping - with food, illness and, to a lesser degree, with emotions - which is why its important to test it regularly.
Don't blame yourself for not noticing - these symptoms we get creep up on us very slowly and very often the diabetic themselves doesn't realise themselves how bad things have got until something happens to make them take notice.
Unfortunately GPs rarely recommend a glucose monitor because if they did then they would have to supply one and prescribe the test strips, which are expensive. There are guidelines that they should supply a monitor but most don't unless the patient is on certain kinds of meds that could cause a hypo (very low blood sugar).