I have to say I don't go with the blood type - food groups thing. Seems very unscientific to me, though I know many folk are interested in it.

I've suffered from reactive hypoglycaemia for years and the symptoms you describe are what I used to get when my blood sugar was very low or dropped very fast, without necessarily getting actually hypo low.

Yes - occasionally, I get them when eating lean protein and no fat, still. As far as I can find out:

If you eat fat, your body will use that for energy.
If you don't it will use the protein. Somewhere along the line of doing this, you make glucose - my biochemistry is very hazy now, someone (Nat?) will know more about this.

Whether or not you make enough glucose to provoke an insulin reaction, I don't know, but given the symptoms it seems possible.

I guess the answer is easy and pleasant - we need to eat plenty of fat with our protein. I now deliberately add oil salad dressings to a lunch that might otherwise been just lean chicken and salad, for just that reason - or I eat full fat greek yoghurt as dessert, or finish with coffee and cream

Take care, Jay