You're correct of course about the fallacy of the phrase "natural chemical balance" - I could have explained myself a little better there. What I was trying to get at was a certain predisposition to anxious states - I'm uncertain exactly how this pans out (genetic? behavioural?) but it would seem that certain individuals have less natural (ie: instinctive) resistance to these states. Tonight I've had a beer & several handrolled fags & a prescription serotonin inhibitor & also some Kava Kava extract earlier on in the day to help take the edge off things & drop off to sleep. Even without taking into account god-knows-what sort of agents were in the food I ate, I'm far from anything like a "natural" chemical balance.
Regarding the GP incident, it was approaching 10 years ago, & remains (almost) a one-off in my dealings with the medical world. However, I didn't want to give the impression that I'm blindly & passively reliant upon the say-so of GPs or therapists. I won't need to tell you that at times, some outside intereference is required simply to break the chain of behaviour. In general, I distrust the reliance upon prescription / over-the-counter drugs (& especially the manner in which paracetemol is so widely trusted & eaten like sweeties), but I've found them useful as a short-term measure.
But it's mightily encouraging to hear the opinions of someone who's managed to break the cycle, & hugely encouraging to know that there are better options out there. Until now, I think I've been guilty of looking for sticking plasters & somewhat afraid to confront the deeper issues & thus gain more permanent relief. Ta v for the advice.