I have decided now that the atenolol is not helping. I continued with it for all of last week, got Quite Bad on Sunday (I think) again and then decided to give it a rest.
Last week was better than the week before. I did some writing for the X-blog (it has actual readers now! I've even met one of them), and got out of the house a bit more. But I have found my limits, and discovered I am still overwhelmed by crowds, prone to distraction, and have had episodes of feeling faint. No absence seizures, that I've noticed, but intermittent aphasia.
Today I went back to the GP, laid out all that. My general bloods have come back OK and I am going to Neurology at Homerton Hospital on Monday 14th January. I am so pleased about this.