"can't get any advice as too what to do next from a strange woman at Preston ."
Women in Preston are like that. I trapped one, at the time that panda with a Bolton accent was advertising some jar of babysick to put on chicken "Stick a fork in me - I'm done!"
Mind, she want to be taken on Saddleworth moor - odd and somewhat chilly, but hey....
By the way your GP may well charge up to £20 for the letter. Still, worth it if it gets him in. But warn him about women from Preston. And Dumbarton, oh and Brixton.