I know exactly how you feel! Realizing that your doctor doesn't have all the answers is a SCARY thing. Before my allergy/eczema issues, I used to think that since I was a pretty healthy person... anytime a a medical issue would arise, I could just go to the doctor, get a prescription and would be done with the medical issue when the prescription ran out.
That is NOT the case with allergies and eczema. It's an ongoing issue and the best type of doctor to find is a specialist: a dermatologist or an allergist. I've used both at the same time and had great results. The best type of doctor to find (for contact dermatitis) is a dermatologist who specializes in allergy patch testing. They can change your world! It certainly did for me.
Doctors can be expensive, though, and specialists can have quite the waiting list. In the meantime, snag a copy of the Health Disrupter Journal to help you pinpoint what's causing your reactions. Also, head on over to my Pinterest page because there are a couple nickel allergy boards there. And make sure to check out the blog, Nickely Challenged and the facebook group called "Nickel Allergy".
Not everybody allergic to nickel needs to be concerned about nickel in food. A dermatologist I saw said that I react to nickel like poison ivy, but was skeptical about changing my diet. He said it very rarely made a difference in people, even with extreme skin reactions. I ended up trying a low-nickel diet (here's a list of foods high in nickel) and saw no difference at all. I can keep my skin clear for months while eating foods high in nickel, but still can't touch it without a reaction. Right now, my fingers are still healing from nickel exposure from about a month ago, grrrr.
Best of luck in your journey! Check back in soon!