Wow, it was nearly a year ago since I posted this. Thought I would give an update. I got up to the 10mg of nortryptiline and it helped to get my sleep cycles back into some kind of regularity. After I had been getting a reasonable night sleep for a couple of months, I decided to come off the nortriptyline as I was very keen to be off all pharamaceuticals. I went cold turkey first off as I was on such a low dose, but I started waking up with continuous brains zaps throughout the night. So I started taking the medication again and slowly weaned myself off at a quarter of a tablet every couple of weeks until I was off it totally and still sleeping reasonbly well. I am now practicing meditation and have been working on getting my digestion sorted which has helped the anxiety and sleep greatly. Herbal tea before bed also helps to get a good nights sleep.