Knickers you poor thing, you sound like you're going through a rough patch. Are you the lady who couldn't get on the august 2007 postnatal thread? We have a new thread which you can try getting onto.
We'd love to offer our support, a few of us are going through bad patches and the girls on the thread have been great. Your post sounded like someone who is very very hard on themselves, and maybe you should be kinder. Life with a 6 month old baby isn't easy, we've all struggled and felt frumpy and miserable at times. You aren't alone, and you haven't failed at anything.
I have to go to bed now, I'm exhausted, but please do pop in, we all have a good moan there. x