certified gluten-free products and salad dressing

[ironictruth]

I am trying to limit processed foods but have a few things I am still using. I think I am still getting glutened as the skipping heart beats, faint feeling, nausea and numbness are still occurring. Probably a trace amount adding up.

My celiac sibling is very very sensitive and only dabbles in processed foods so I am thinking this may be my issue. I was recently glutened though (positive through dgp on 9/15) and have marked duodenditis (8/27), so maybe I am still recovering. 

I have trouble with balsamic vinegar (recent dumb experiment) so was steering clear of making my own dressing with that. I had purchased a certified gluten-free Drew's dressing and feel funny. 

I read online somewhere random and possibly not trustworthy that Drew's uses the same equipment for wheat containing and non gluten products. 

Can someone school this rookie? Can you be certified gluten free on shared equipment? Should I start calling every company I do use!? I use Canyon bread for toast. 

Is there a list of items which are not produced in a facility with gluten?

Any suggestions on dressings that would be safe? I was trying to get some good nutrients in with salads. 

I feel like I am taking away more and more foods each day. Gluten, dairy, soy, most seasonings except for salt/Pepper, coffee, wine, my beloved hot sauce, even hummus pissed off my tummy and thyroid last week.