Sorry to hear you are no better on the diet. I have had the same problem, although I only have mild stomach issues. My symptoms are feeling very unwell, headaches and DH. I went GF in 2011 and have felt worse for it, I like you thought it was cross contamination so we completely stopped gluten coming into our home but it made no difference.
Looking back I probably had symptoms of CD for well over 30 years before diagnosis, the symptoms varied from rashes,asthma,stomach pain, hair loss etc which would come and go. I think I had been poisoning my body with gluten without knowing it for so long that now it cannot cope, it can get confused and start an autoimmune response to things that arent gluten.
If you search on Youtube for gluten free there are several doctors advising of leaky gut syndrome, basically what happens your gut wall becomes permeable and you start reacting to other things as well as gluten. One video I watched advised that the worst thing someone with an issue with gluten can do is go on a gluten free diet and eat other grains, like rice and corn and the commercial gluten free breads/pasta products available to us. They said it is better to eat fresh fruit, veg and meat and to heal before starting on these other non gf grains.
I stopped eating dairy and felt much better for it, although i have started to eat them again as I found dairy much harder to do without. I think I can still react but not as severely or as often as before
I know you have said you are already on a very limited diet and I am wondering whether one of the foods you are eating could be causing you an issue, perhaps the pasta or rice? Could you try to stop eating this for a week to see if you feel better?
Hope this is helpful and you start to feel better soon.