I am reading this a couple of months down the line from losing a dearly loved sister in law to this insidious illness.
She was not the world's shittest mother and NOR ARE YOU. I promise. The fact that you are concerned about harm coming to your baby shows that you are not.
She was a fab mum, did great through her first pregnancy and early years of motherhood only to be hit by PND after a traumatic second birth, left with prolapse, and her baby had severe reflux before being identified as having a cow's milk protein allergy. (Diagnosed at about four months, but I don't know how early it's possible to test.) Baby cried constantly due to her discomfort, and couldn't be put down for long.
Our family is small and at a distance from one another and on top of this, lockdown, and little access to social interaction.
SIL sought some therapy but I don't know how honest she will have been about the depth of her feelings. The inquest we're awaiting may reveal something of that.
We, her brother and I, didn't know at all. (I feel like the world's shittest sister in law.) If we had, I'd have gone and not left her side.
Instead, she put a brace face on, so to speak. (She was inclined that way, but it was always a façade, it seems.) We hadn't seen her for months because of Covid. I think we might have seen the cracks if we'd been able to visit.
It's brave to do what you're doing, vocalise how you're feeling to your partner, MH professionals and us. Don't be afraid to say you need more help, please. Depending on where you are in the country, there may be some residential care for you and baby. I will wish every day of my life that she had sought more help, more support.
Her partner was supportive as best he knew how, but clearly didn't get it in the way he now does, sadly. He's now raising two tiny children alone.
Yes, it's tough living with someone with depression but this is a whole different thing. This is a torrent of hormones that fluctuate wildly, combined with caring for a newborn, combined with losing touch with your sense of self, your relationship changing overnight, and more. In a pandemic too. You shouldn't feel bad for this - you've not chosen this.
I'm of the belief, now bereaved, that PND needs to be monitored very, very closely and considered a potential crisis situation.
I really don't want to frighten you (or anyone else) but I think you may already know you're at risk of sinking further. Some of the things you've said have echoes of a message she left and the phrases she searched online - things we discovered after the fact.
You are a good mum. You are doing your best. What you are feeling is understandable. It isn't the 'baby blues', despite your username. That downplays it. It's clearly a lot harder than that.
If you haven't already, search for a PND support group. You need to know it's not just you. Please, please don't be afraid of judgement.
If you want to PM me for support, please do. I live in Hertfordshire, if you're anywhere near and I can be of practical help, please say.