sorry to be harsh
You come to a country that is universally hailed as the best place to eat in Europe at the moment and spend all your time complaining rather than exploring. Giving our ex-colonial cousins a bad name don't you think
London has just thousands of places that are wonderful to eat ( I seem to have listed most of them for you ) and yet none seem to hit the spot.
This is not just a britcentric view. I have spent huge amounts of time eatingout in the US and it is as good or bad as London. There is no magical thing about a restaurant in NY. I have eaten as much trash there as anywhere and been ripped off just as much. I have also had as many magical nights in London as any I have had on my frequent visits to the US
If you want more I will gladly list as many different types as you want but I suspect the complaining is more pleasurable for you than the eating.