I agree with @fonda. I too have idiopathic PN, and have had the million dollar work up at my local university hospital. The fact that it is idiopathic does not in any way mean that the doctors are idiots. This disease is very difficult, in part because there is comparatively little known about it. Also, it is chronic and manifests in many different ways. Even after the work up by university experts, I am in the same place as @summertime4. Some things are just unknown. Let's hope there are answers soon.
Like all of us who are patients, I have tried numerous meds and different alternatives, without any real change. What makes it so hard in part, is that the goal is a moving target. My symptoms are effected by different meds, changing moods, the weather, the seasons, what I'm wearing and doing, and many other variables. Trying to decide specifically what is working or not is nearly impossible.
I'm going to be on low dose naltrexone soon. I'll post if it helps.