Hi OP, not to minimise what you are going through and I don't have a like-for-like experience but a couple of years ago I was pregnant, with a baby that we had discussed having beforehand. Upon conception, everything changed for me. It was all blackness and I seen absolutely no goodness coming from it. I was sure my partner would grow to hate me, I would be a single mum, I'd lose my career, I'd destroy my body, I'd end up with PND and be ill. It was doom, doom and more doom. My partner would tell me I wasn't thinking straight, that it would all work out, that I should speak to the GP etc. I honestly just thought he was fuck*n stupid for not seeing the reality that was SO OBVIOUS.
I had a medical abortion. I had a fleeting "am I sure" before taking the second tablet but I went through with it. It was the first time I had felt any relief from the blackness in weeks.
Two weeks later, my hormones settled down and my mind cleared. I couldn't believe what I'd done. I couldn't relate to the person I had been. It was so obvious, in hindsight, that I had been in some sort of crisis.
It's now several years later and I still wish I had got the appropriate help and chosen a different path. And, if I'm honest, I have a little resentment for my Partner that he didnt push harder, though I know that's unreasonable.
By all means try to put a plan in place that will put you at ease for now, but I would put a safety net in place, such as family or foster care, caring for the baby for the first week or two, to see how you feel once your hormones start to level out. I'm truly sorry you are going through this.