Rosie, as long as you don't yet have diabetes, you don't need to be as scared about the risks as you are. The loss of organs comes after they don't get enough oxygen for a long time, or don't get the 'waste' removed after a long time. (These are not overnight symptoms, but ones that take years.) The blood system's job is to carry the oxygen/wastes, and it can't if it's full of glucose. Smaller meals more often keeps the blood glucose lower. Staying active helps pump the blood better.
Once we've reached a certain age (60 and you and I are both there) they allow our readings to be a little higher than they did when we were younger. That's because we probably don't have enough time to begin that kind of damage.
So, eat sensible, stay active and test periodically and you don't need to fear it.