So sorry you are having such a hard time. When you say "so the doctors say" what doctors are you referring too? If none the doctors are in the mental health field, I would highly recommend you find one soon. I don't know what the medical system is like in the UK.

Just reading what you have written says to me 'depression,' but I am not a medical or mental health professional.

I am sure you have not failed your children, even though it may feel this way. If these children are a produce of this relationship you wrote about, why do you feel that is wrong for any of them to live with dad? Yes, as Moms we all feel it our responsibility to be the person taking care of the children...that maternal instinct kicks in.

You are just going through a rough spot and it is understandable that you would feel badly about things. How do you know you are to blame? That is rather a harsh assessment of yourself.

If you can, try to avoid the triggers that toss you into the dark. If the triggers have anything to do with the children or the ex, I can see it would be hard to avoid those triggers.

The bottom line is to take care of YOU!!

Stay in touch here...there are many on this forum who have great listening hears and we all want to help in whatever way we can.