Why are parents so good at making you feel guilty?

Since May, Mother has been on and on about going away during the summer hols, I've been putting her off, but since E has bottled on travelling again, I've sorta become resigned to it.
Anyway, she wanted to go to Lanzarote, a place I've been before and she's been many, many times and believe me, it gets its nickname Lanza-grotty for a good reason!
I hate it, its boring, full of nasty ex-pats determined to set up London-by-the-sea and its hot. Christ is it hot. I can't bear to be out in anything higher than 15 degrees for long and its 30+ over there.
And me and Welshy are half-heartedly looking for somewhere to live together, so its 500 quid, money I dont really have and a waste of my leave to go to somewhere I dont really like. Anyway, last Tuesday she guilted me into going.
"I'm all on my own, all my friends have their own families and I'm alone in the world! Alone, neglected, unloved, unappreciated." etc.
So I said I'd look into getting some leave which I did so on Monday.
Only problem is, I've gotten all the week off apart from the Thurs, she wanted to fly out for, there aint flights on Fridays or Weekends.
So I've asked a few people, tried to get a swap, but we're short-staffed so its no good.
So now she's running about sobbing and stropping about:
"You did this on purpose! You could have asked last week" Yeah, like i'm REALLY gonna be able to chase our leave guy to his Tent where he was camping in order to get time off.
"I've ruined her summer holidays, she's now unable to go anywhere. And its all YOUR fault. Everyone else gets to go places and she can't. She was so looking forward to it, now she has nothing to do all summer."
And shit on toast how i'm hearing about it.
Over and Over and Over
Everything she can find to shout at me she does, opening a window, not being able to eat the tea she's cooked as its far to hot for a full roast, for falling asleep.

Sometimes I really just want to scream at her and make her see all that I do for her, the years I've wasted, how I've put aside my own happiness for her, how I bend over backwards for her, how I have to put her first when both her and Welshy make claims on my time. When the Brat couldnt even be bothered to drive down to sainsburys to get shopping, when she was ill in hospital, how I worked, spent all my free time visiting her, or looking after the house and him, struggling down to the shops on the bus with bags and bags of shopping while he stormed about moodily, and she lay sick in bed.

But there's no point in that. And now i've 5 wasted leave days, unless she gets outta her strop and decides to drag me off to some other shithole.

To Stop this being a completly self-pitying post.
Hurrah for Welshy who despite his own obvious boredom took me to see a Horseball tournament on Saturday and then let me watch Hickstead all afternoon!

Horseball - Rugby on Horseback (I SO wanna go!)