Hi
@SueinLincs and welcome to the forum.
Reactive Hypoglycaemia is like a worse form of T2 Diabetes. The difference is that in a T2D the pancreas won't (usually) produce enough insulin to both overcome insulin resistance and drive Blood Glucose down beyond normal levels into the dangerous hypo range.
Until somebody with RH comes along with advice, my 2p worth is that you should:
A) Avoid carb containing food as much as possible - eat meat, fish, eggs, hard cheese and ultra low carb veg such as leafy greens, celery, cucumber etc.
B). Use your BG meter to test your reaction at short intervals after eating a food with carbs in order to find ones which cause the least (slowest) reaction. These will then be the ones to eat both to halt the path to a hypo and will be the safest cars to eat for a 'normal meal'.
As a Type 2 I can say that we are all different in our reaction to carbs. Some T2's can eat apples or carrots, but they spike my BG far too much to eat more than half of one. And I can't even consider porridge, bread, rice, fruit juice or tropical fruit. Yet some T2's actually have a small portion of porridge (or even All Bran) for breakfast without harm.
This is why I suggest you discover which foods work as a low GI in your digestive system. They may be ones that aren't obvious because the truth is that the GI of a food depends upon who exactly is eating it!