You have to add in how long you were an undiagnosed Celiac....

I’ve been to restaurants for lunch with people from work and not eaten anything.  One time I just had a bowl of white rice.  The restaurant didn’t care and nobody made any nasty comments.  It took some bravery on my part to do that but it turned out fine. I just tell people I’m there for their company, which is more important to me than the food.

From your first post, tests 1-4 are individual antibody tests used to detect celiac disease. #5 is what we call "total IGA" which is used to check for IGA deficiency. If a person is IGA deficient, it can skew their individual IGA test scores down toward the negative range and generate false negatives. You are not IGA deficient. Test #4 from your first post, the tTG-IGA, is the most popular test ordered by physicians and considered to be the best single test for diagnosing celiac disease. It is relatively inexpensive to run and it combines excellent specificity with excellent reliability. You were negative for this one. The reason could have been, however, that you had been eating a reduced gluten diet. The one positive test you had, the DGP-IGG, is not as specific for celiac disease as is the tTG-IGA but certainly can indicate that you do have celiac disease, particularly if you were skimping on gluten when the blood draw was done. The endoscopy with biopsy of the small bowel lining is considered to be the gold standard of diagnostics for celiac disease. But it still requires that you have been eating generous amounts of gluten for weeks/months to be valid. Otherwise, the villous lining begins to heal and nothing shows from the biopsy. The problem might be finding a GI doc willing to do an endoscopy/biopsy on the elevated DGP-IGG alone. He/she may want to repeat the antibody panel first. Your other option is to forego an official celiac diagnosis and commit to seriously eating gluten free and see if your symptoms improve. You would not know whether you have celiac disease or NCGS but the antidote for either is the same. You never mentioned your symptoms. What led you to get tested for celiac disease?

Ultimately you have to be responsible for your own health, regardless of how it might affect others, and this is especially true if you have both celiac disease and a severe nut allergy. Eating out is the most common source of gluten contamination, even in restaurants that have gluten-free menus.  Celiac.com has published a book on our site by Jean Duane PhD called Gluten-Centric Culture, which covers many of the social aspects of having celiac disease: This chapter in particular covers issues around eating with family and others - Gluten-Centric Culture: Chapter 5 - Grabbing A Bite Together:    

It looks like you had a positive blood test for celiac disease, so the next step could be an endoscopy to confirm celiac disease.  This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease.