Travel nerves

Husband has developed an early warning system concerning my rising nervousness before travels.
I can hide it, but I cannot erase it. It is in my genes.
Which is especially funny as my late father, whom I miss so much, has not only seen most parts of the world, but also took us as children to many countries in Europe (with a VW and a tent, and the car packed as only a man from the marine can pack - my sister and I sat on the back seat on four sleeping bags, and when we finally reached our destination, in the early years my father built (!) a bench from wood for us to sit on - bringing with us the round camping table he had fitted exactly over the spare wheel of the VW (in front).

As I was the eldest and there were no sons, I was trained to take it all without batting my long eyelashes - so nobody who will err with me through the woods (in summer) will die of famine.
My father's family, the practical ones with the joie de vivre: restless. The names of my mother's family I can effortless trace back to the 16th century - they had always stayed in the 'Altes Land' near Hamburg - which tells everything.
Do not misunderstand me: I love to be in foreign countries - and, as I told you, I try every year a form of 'survival training' that makes some of my women friends shudder, (though my male friends get that cryptical glint in their eyes). For a whole month I stay on my own in an English or Scottish town or city where I know nobody - and till now I always managed very well.
I like to be in new surroundings - but I hate travelling. No, that's not right. I even like travelling: I hate catching the train. Flying is another cup of tea: I utterly LOVE to start and land - and as I go now by air I can be quite serene.  IF there weren't the question of clothes.
Husband smiles when he sees me puzzling over 'the perfect wardrobe', studying the blog 'The Vivienne Files' and drawing combinations of trousers, skirts and shoes (you always need at least 3 pairs - ballerinas, kitten heels (nowadays - a curtsy to age)  and loafers for trousers) I don't want to take too much luggage (though I always do - but I get better every time), I downsize, but then in June in England it can be cold (in Edinburgh two years ago people were wearing their winter coats, no joke), or rainy, or - as I experienced it as a student: there comes a heat wave. I like to be prepared! (Though nowadays there is always the possibility to buy something one has forgotten at Zara or H&M).
As you cannot help me with the weather forecast you can do me another favour, please: if you have special tips what I MUST see/eat/test in London, please tell me! Thank you!