Re: very worried, please reply
I'm in the UK too, about 1 year ago I was experiencing very similar symptoms to what you are describing, unfortunately for me after many visits to my GP and numerous specialists, I remained undiagnosed, and all my test results were always negative.
Your post struck me because I used to smoke, and when I did it would exacerbate my symptoms which puzzled all of the doctors and me.
I eventually gave up on the NHS after 10 months of nothing more than a diagnosis of depression, and started to do my own research, when I stubbled upon Lyme Disease. I had actually been tested for this previously 3 times on the NHS, but I soon learnt that testing for this disease was very disputed and unreliable.
Eventually I managed to find an LLMD in the UK (lyme literate medical doctor) and was retested and evaluated and was diagnosed with Lyme in November 10. I have now been on treatment for 2 months.
There are many things that could be contributing to your symptoms, I am obviously not a doctor, and am not suggesting that you have Lyme Disease either. But I just wanted to relate my story, and perhaps suggest that you could visit the Lyme board, and make some enquiries there too. I do hope you find some answers soon.
Best of luck