Practicality was forced on me previously due to endless rain, wind and rurality. Now I am somewhere a little more easy going and feel odd wearing those old things.
So like an ugly rich old husband you thought you loved him because he gave you what you needed. But now you don't need him you've realised you can't stand the sight of him. Time to divorce, pass him on to someone who'll truly appreciate him.
I have always preferred skirts/dresses, but more casual than glam. I don't really do glam. Always felt uncomfortable in jeans/trousers. So I began to build a new wardrobe with skirts, etc, and keep wondering if the weather will eventually destroy them, as I don't yet drive (was going to learn before covid scuppered it) so need to walk a lot.
And now your carefully curated wardrobe of fledgeling skirts are at risk of being drowned in the rain, swept away in a torrent of oily water, broken sticks and unidentifiable black things in the gutter unless you keep them wrapped safe and warm and close to your heart. It's bollocks, you know 
. Clothes shrink in the washing machine and tumble dryer, not in the rain. Unless you've done something really awful to upset God and he's raining down hailstones made of blades upon your unrepentant head, the weather is not going to destroy your clothes.
I wouldn't call it guilt, but more like a distrust of things that aren't fit for climbing a Cumbrian fell!
When was the last time you walked up a fell and how often do you do it? Do you actually need these clothes at all or are they just your familiar comfort blanket? Go put your blankie away in the box in the loft, you're a big girl now!
could anyone advise me what to wear to stop rain bothering my clothes?
There you go again, your clothes aren't bothered, the "precious" is all in your head 
(Has visions of the OP stroking her skirts and muttering to herself, like the scraggy pixie creature in Lord Of The Rings).
I can't for the life of me work out how to cover myself in heavy rain if I like mini length skirts.
You don't. You get wet😜 . You take an umbrella and your wool coat, add some knee high boots and you accept a degree of dampness in exchange for looking good and feeling like yourself. Or you give up and get some jeans/jumpers that feel as much like "you" as possible (considering you don't like them) and you suck it up for 3 months, in exchange for not having biting winds whipping your wet legs at zero degrees in the dark, the whole time fantasising about spring and the return of your faithful friends the skirts. Or some combination thereof. See, you already need two winter wardrobes, one for dry or indoor days and one for wet days.
The only thing I have seen is this (picture) and the cape puts me right off.
Ah the coat, what can I say? Not a lot, for fear of it scurrying off to the back of the cupboard to cry. It's trying so hard, bless it. Born sensible and practical but trying to look glamorously girly. Top marks for effort, whispers but it's fugly . I don't mind the cape myself, but I'd want a better fabric. Something softer feeling and cozier looking, which would also make the cape hang better, although it wouldn't be waterproof then. And pink, you can tell in its heart it wants to be pink. Dusty pink to blend in with the grey winter skies.