I had some (non RC related) anxiety issues and my psychiatrist prescribed some benzodiazepines for occasional use... (Specifically, Lorazapam... it's in the same family as Xanax.) I'm not supposed to use them more than say, twice a week. And I don't even use them that often.
I asked my Dr. specifically about flying RC while on it. He said that at my dose it should not be a problem. I re-explained the safety issues involved because I don't think he understands that these things are flying sawblades. He still said that I should be fine... he didn't believe that it would effect my judgement, just my anxiety.
So eventually, I happened to have an anxiety day on the weekend and I went flying. The net result was that I was less anxious about crashing my heli. I wasn't relaxed exactly, any flight involves a lot of butt-clenching, but I was stable in thought... enough to clearly think through my recovery moves, instead of panicing. I was flying lower than I usually do. I was falling a bit lower than I usually would, and doing an extra pirouet. I was letting the heli get into orientations that I would normally only do in the sim.
And now, a few months later, I'm not on the lorazapam at all, but my flying stays at the new, lower, slightly more aggressive style.
I think, in a very slight way, the drug helped me learn to relax on the sticks. I've been able to continue relaxing without it.
For everyone wanting to experiment with your mind... If there is something wrong with your mind, or you just don't like something that it does, please see a professional. I don't care if it is a psychiatrist, psycologist, natropath or a neurologist. Many of these people actually do have proven treatments (some not involving drugs) that can help you.
For the original poster, and those like him: Your complaint about nervous hands while flying is a legitimate thing to be addressed by a healthcare professional. Explain what you do and why it matters, and get good treatment.