Good to hear that you got a diagnosis. It would appear that your condition is beyond lactose intolerance and that you might in fact be allergic to the casein protein in dairy. I recently developped that problem its toook me 6 months before we figured it out and I had all the aganizing sysmptoms you described. You develop a true sense humility in talking about your symptoms.
I have to avoid all dairy now, and as you mention dairy is in everything. Read the labels to avoid unintended exposure. Its in most bread, chocolate and other products. Look for a "vegan" designation on things. Not that you need to avoid meat. But be careful of processed products.
I have since met with a nutritionist to ensure I get the proper nutrients now that my eating choice have been significantly impacted. She told me the same thing about the issues with dairy. She said she would have guided me away from dairy even if I didn't have the problem, as per the reasons you cited in your last post. You are correct that there are more efficient ways to get the viatmins and nutrients that we think we get from dairy, mnay more ways.