Big bottom on a bike - cycling the coast of the UK - the plan

It seems silly that, as someone who has walked up mountains and been trekking, I should feel so intimidated by the concept of a long cycle tour. Maybe it is just that there is a whole new bike language to learn, or maybe it is the additional complexity imposed by having to think about a bicycle as well as myself when I am used to just having to think about where to place my own two feet. There is also the whole padded shorts and cycle kit thing! I am 5 foot 8 , a size 14 and not really overweight ( although like most people - I can pinch an inch!) but it seems that I must label myself as having a 'big bottom' as I have had to buy XL cycle shorts, and what with the Lycra and cycling padding there is definitely a large bottom overlap on all sides when I sit on my saddle!
I have also been dithering over what clothing to take - grappling with what I need in order to stay warm and dry whilst cycling and camping from 1 March until some time in the summer, but trying to keep the weight to a minimum. The kitchen scales have been pressed into action - should I take my big fleece or 2 thin ones??? which combination weighs more.....  Can I buy women's cycling specific items in a colour other than pink! (More about my final chosen kit in a later blog).
The plan is to use B&Bs or hostels when it is too cold to camp and feel happy, or when I feel like crying. The rest of the time we will be camping to keep our costs down but I do have an agreed, slightly extravagant, daily tea-shop allowance in our budget - to keep morale high!

I am excited to explore the coast of the UK, to challenge myself to do something I think is quite a tall order, and to improve my fitness - hopefully without ending up with man thighs! 

It is only about a week before our planned departure.... Eek!