Muffin - I have been depressed before (and also have had two manic episodes resulting in a stay in a couple of lovely mental hospitals. I spent a good few years having panic attacks most days. And most nights I would have to try to sleep whilst hallucinating. But things are getting better and better the older I get (I'm now the ripe old age of 34).
I have been lucky that I have a supportive DH & friends. But I have times when I have felt there is literally NO ONE I could tell the things I am thinking about as they are so dark/weird/self-absorbed/self-pitying/unbeliavable.
At those times I rang the Samaritans. You can tell them ANYTHING you want to. They will not judge you they are the most amazing people.
Sometimes I would have dark thoughts in my head for days on end. Wanting to hurt myself. But once I had talked it all through, with someone anonymous it no longer had any power over me and I could move on.
I accepted that I had these thoughts but that in reality I didn't want to carry them through.
As for ended my life I would never do that to my children. My father lost his mother as a young child and the scars run deep. They are never better of without us no matter how terrible a job we think we are doing.
Please think about ringing the Samaritans. they have heard it all and far worse before.
There is always a way of making things better