Hi again Andrew,
Further to your PM, from what I have read on the forum it does seem as though your anxieties may be coming out of your medical problems. I know absolutely nothing about WPWS.
However, I can tell from what little you have said about your diabetes so far that you have no reason to be afraid because you sound to be a well controlled Type 2 and with help from others on this forum then you should be able to improve that control still further. As a Type 2 on metformin only then nothing nasty is likely to happen to you in the short term. Going below 4.0 is technically classed as being too low - i.e. "hypo" but all you need to do in such instances is to take a little bit of something to eat to raise your blood sugar levels a little bit.
As far as avoiding the long term complications that all Type 2s are at risk of you will need to maintain a well-controlled blood glucose level by learning to avoid your levels going too high - i.e. "spiking" approximately one hour after eating. To do that you need to get to understand through testing how much carbohydrate you can eat at a particular time of day - e.g. many Type 2s including me cannot eat very much carbohydrate in a morning at breakfast and because of that I usually eat a grilled or fried in olive or rape-seed oil breakfast.
The food type that you ought to be wary of are the starchy carbohydrates such as cereals, bread, potatoes, rice and pasta etc. Most Type 2s get a big improvement by cutting back on those - e.g. I have cut out nearly all - but not all - cereal and bread out of my diet.
Testing will soon tell you what are the problem foods that you need to be careful with - especially if you test one hour and two hours after you have finished eating a particular food or a major meal.
Just take things slowly and make little changes at a time.
Best wishes - John