Thank you one and all for your suggestions. My infection really was an infection: it cultured out. The second one could have been a left over from the first, inproperly treated, one.
I have a problem with cranberry juice: it makes me sick. Maybe if I drank small quantities of it, I could get used to it. And lots more water.
I have a cut out saddle to try, and have cycling shorts on order. I sure hope something works.
As you get old, none of your parts work very well any more. I have in the past ridden 50 miles on a Brooks leather saddle. Now that hurt, but no infections! And that is part of my glorious past.