I've only just read your post - EEEKK!
This is no time to throw in the towel! Even with all these health complaints your wife can go on living. Please please get to your local hospital and get help with this. Find out what to do if your wife's blood sugar goes low yourself - maybe you can get the glucagon injection to keep in case of these emergencies? You need to learn how to inject this if your wife cannot.
Also, as Jeannie mentioned, find out about the glycemic index (GI) - look on the web! Find out exactly how food will affect your wife's blood sugars. (I have found that coke isn't actually that quick acting on blood sugar, even though it is full of sugar - I find lucozade to be much better for hypos.) It must be hard that your wife has so many things to consider, so I urge you to see a dietician. You really need to seek professional advice, and seek it together.
I'm really thinking of you both right now and I sincerely hope this gets better soon. Keep us updated!