Depression is a funny thing

As some of you know, I had a left lacunar stroke a few years back, and one of the things it left me with was my brain deciding it needed help in the form of medication. 
It was to keep me on an even keel.
Without it, I slip into the most maudlin moods.
I did try 6 months minus without , and it was hellish.
It was like having extreme pms all the time.
So I relented and agreed with the Doctors that I needed the chemicals.
I've got to say I am lucky.
I'm on the smallest dosage and for 90% of the time I'm fine.
In fact I giggled with the Doctors in Canada that I'd be banging my head off the wall if it hadnt been for that medication , in fat told the occupational health doctor the same. And I know it's got me through some very hard times in the last 9 months.
But, for some reason this weekend, doubt crept in, and I felt the fog descend.
My sister above me, annoyed me no end.
She's Mother Theresa in her mind, rushing off to do good deeds for strangers, and yet never helping out with her own mother ( last time was Christmas Day). Or doing good deeds for us. Not like there is anything I want done! But.... She expects us to always been on call for her mess, to help clean up whatever crapola she gets into, forgetting when she does some stuff it's not just her life she screws up, but ours implodes too!
She is the one, that makes me want to be an only child.
I wish as wouldn't pop in, love the days she doesn't come near.
But she doesn't get why it annoys me, as it's all me me me. 
Of course her aches and pains are worse than mine etc.
I  was missing a friend who went back to Canada to live, he'll knows why now as they went back Months ago and for some reason they've sprung to mind nd I think I miss their uncomplicated view of life! Ok it annoyed me every so often, but, I kind of miss it, and the link they gave me to Canada.
I feel all my friends are far away. Though I've wonderful friends in Jackie ( whom I'll see this week) and lovely twitter / fb friends but, for some reason it's all far away.
I booked my flight for July 2013 ,will be away for 29 days.
Thought that would help then I thought , I wish this was a one way ticket, what's keeping me here? Mother, yea, but I've no one really. And I don't mean someone to love etc, but, just nothing that's tied me to here for me, and I don't want to grow old on my own here without a real life. I'm treading water
I feel weak as I need medication while others I know struggle and cope without it.
They manage and poo the idea of medication , I know I did hence why I had those 6 months off it!
I feel karma is biting my bum stating silly woman this is what you get for stating it's keeping you on an even keel. Thinking life is not bad. It's the big Monty Phython foot squashing things reminding me not to be complacent.
I read Marion Keyes account of her depression. I should be grateful I'm not as bad as that, but I don't think anyone understands depression unless they too have had bouts or suffers.
It's funny, well, I have visualisation of how it makes me feel. 

Bit like the cable car at Grouse Mountain when you go through the clouds, and it's an inversion , that's me all weekend, can't see normal as its below and beneath the clouds.