Right. Update. Firstly, thanks to Sassy especially and Jolly, Laugh, Tulip, 314 and Freaky. For everyone, and especially those of you who have boosted my self esteem, I’m just regretting Rule 10. 
Hopefully all the following will answer your specific points.
I’m sorry I’m this seems all about me, but I don’t want to be seen to be the person who is pushing into the crowd of friends all talking, and giving my opinion on life, the universe etc. I’ll try to respond in future to other comments which come up, and hope that I can say something useful.
Anyway. Had the chat. I’ve just typed out a long response, but whilst its cathartic, its tmi. I think the short answer is that the factors 1 and 3 in Sassy’s post have come into play, with 3 - the sex drive – being a legacy of 1 - the lack of recent experience - and what recent experience there was, wasn’t great.
However, the killer is that whilst she told me briefly about it –superficially, and the above is my interpretation – she didn’t want to talk about it. She got pissed off that I wanted to talk, and effectively said that I should accept her position rather than try to understand. The other background that came out strongly was that after a couple of months going out we didn’t really know one another and she wouldn’t want to go to bed with anyone who she didn’t really know (ie me, at the moment). So even if there weren’t any sexual issues for her, the inference is that we really don’t know one another, and whilst she did make concessions on communication, it was dictated by her position rather than mine.
We parted today, not in a good place with one another.
I suspect that the advice would be that I’m flogging a dead horse, and that I should cut my losses and run. And even if I she and I did pursue things, our sex life might be restricted to infrequent staid occasions rather than that spontaneous passion that could get one arrested if performed with the curtains open.
But despite that sensible thought, it hurts. It fecking hurts. My sympathies to anyone else in this position. I now know what it’s like. If I’ve been here before, I’ve forgotten. Rule 3 is true, but a bastard.
And again sorry for the self indulgence. I have tried to dull the pain with wine, and beer. Comments appreciated.