Hi Tracey, I thought I might hear from you on this one ;).
The world looks very different to a reactive hypoglycemic. A verrry short period of time to a reactive hypoglycemic is an hour, not three days. Fruit is better than juice, but fruit is very strong. It has sugars and things that get converted into sugars, but has no fat and no or almost no protein to balance out the sugars.
This spikes blood Sugar to diabetic or near-diabetic levels. The pancreas then releases too much insulin, which pulls blood Sugar down sharply, causing the release of a large amount of counter-regulatory (mostly adrenal) hormones.
This can cause fatigue, depression, fear, anxiety, panic attacks, shakiness, irrational anger, PMS, inability to concentrate, muscle pain, insomnia, crying spells, phobias, hunger, craving for sweets/carbs, feeling like you're going crazy, suicidal tendencies, etc. It's not just fruit that can do this. Starchy carbs like bread, potatoes and pasta do this as well, since they are converted to sugars during the digestive process.
References are scant. Most stuff on the web has quite a bit of misinformation in it. This article describes the symptoms very well:
This article attempts to describe the hormone/blood Sugar relationship. Note that as above this is mostly adrenal related and not digestive related. When symptoms occur <= 2 hours after eating, it's thought to be mostly caused by digestive issues; when it's 2-5 hours after eating, it's thought to be mostly due to adrenal issues.