I didn't know it then, but I was suffering from postnatal depression (PND).
Karen Simpson, 31, also suffered from PND. On Sunday morning, 24 February, she walked to her local Tesco in Burscough, Lancashire to buy some nappies and clear her head, she told her family.
She never came home to her husband, her three-month-old baby daughter, and her two sons. Yesterday, police found her body in a field. My thoughts are with her family and friends.
I would not presume to know what was going through Karen's head when she set out. I only know what I felt when I had PND.
The crushing guilt at not being the mother I wanted to be. The terrible sense that all the joy had been sucked out of my life. And the sure, certain (and, as I now know, totally wrong) conviction that my family would be much better off without me.
Around one in seven to one in 10 mothers suffer from PND. That's an awful lot of women with a condition that can potentially destroy a family. A long-term disorder with symptoms including depression, anxiety, insomnia, and suicidal thoughts – but a disorder which is treatable with talking therapies or antidepressants.
Yet on Monday this week, the Aberdeenshire-based PND Support Network announced that it would be closing through lack of funding.
In 2011, a report on PND from family campaign group 4Children, Suffering in Silence, found that many health trusts don't comply with NICE guidelines on dealing with postnatal depression, and few hold any information on just how many women present with PND.
Frighteningly, it also found a 'chronic lack of awareness' of PND among expectant parents, the public – and medical professionals.
My own attempts to get treatment didn't fill me with confidence. My GP told me, when I went to see her after six months of desperation: "I've had three children, I don't know what's bothering you so much."
When I was pregnant with my second child, I offered to talk to my ante-natal group about the signs of PND. My teacher was uncertain. "I'm not really sure the group wants to think about things like that," she told me.
As if PND is something to be ashamed of, something to brush under the carpet – because heaven forbid that we make motherhood out to be anything other than fluffy clouds of pink-cheeked, gurgling perfection.
I was lucky enough to live near the Anna Freud Centre in North London, and lucky enough to have a clued-up health visitor who referred me there for therapy. Even so, it took three years before I was confident enough to have another child.
Many women don't recover fully because they don't get help. As a volunteer for the Birth Trauma Association, I constantly hear from women who have been fobbed off with 'it's the baby blues, dear' (it's not), offered antidepressants but told they will have to stop breastfeeding (not necessarily), or are given vague promises of 'counselling' (which never materialises).
So what needs to be done? I'd like to see all health trusts offering free antenatal education classes (many of which have fallen victim to cuts) which include detailed information on PND. Women aren't stupid. We want to know what could happen.
We need to be listened to. When we say we're not coping, we don't just want a cup of tea and a pat on the head. We want real, practical help. We want counselling, more funding for support groups and support lines, and the knowledge that we will be believed and not belittled.
And we want a real change in the way both medical professionals and the public regard PND. It is not feeling 'a bit weepy' or 'a bit hormonal': many of us don't cry at all, we just sit and stare.
It is not a result of unreasonably high expectations – unless it's unreasonable to just want to be a good mum and do your best.
And it is not a disease of 'middle class yummy mummies' – it affects all women, of all races, classes and ages.
I never went on my lonely walk in the end. I had a suspicion where it might end, and it wasn't good.
But I'm pretty sure there are more are women out there, right now, walking to nowhere. Please start by talking to someone about how you feel. Turn around and walk back home.
The PANDAS Foundation runs a support line for women suffering from PND - 0843 289 8401