Hello OP, we are really sorry to hear you are feeling this way.
We hope you don't mind, but when these threads are flagged up to us we usually add a link to our Mental Health resources. You can also go to the Samaritans website, or email them on firstname.lastname@example.org. Support from other Mumsnetters is great and we really hope you will be able to take some comfort from your fellow posters, but as other MNers will tell you, it's really a good idea to seek RL help and support as well.
We also like to remind everyone that, although we're awed daily by the astonishing support our members give each other through life's trickier twists and turns, we'd always caution anyone never to give more of themselves to another poster, emotionally or financially, than they can afford to spare.
We are going to move this thread to the Mental Health section shortly.
You've done so well in even posting. Believe me I know where you are coming from. I'm in almost the same place myself, I'm on antidepressants already though and they DO help so please book an appointment with your GP.