I share your frustration, finding a celiac-knowledgeable doc is like finding a needle in a haystack.
I haven't found one yet (GF since '05) but I live in the boonies. If you're anywhere near a major non-profit teaching hospital, you may want to start looking for an internist there.
You might want to get a bone density test (DEXA scan), that can dx osteomalacia but also early onset osteoporosis, which is more likely with Celiac, especially in those not dx till adulthood.
Celiac is inherited. It's something you're born with, triggered by the introduction of gluten into your diet. Like most autoimmune diseases it can wax and wane in severity but it is always there.
Ask your doc to check your thyroid hormones too (they can mess with calcium and vit d), autoimmune thyroid disease is very common in Celiac.