@cloveerforever If you don't mind me asking, how old is your kid? I ask because my wife also had PPD, and holy shit the first year of my daughter's life almost broke us. This isn't to make excuses but maybe to somewhat put her behaviour into context, but my wife turned into a different, and honestly not very nice, person for some time because of it. I hit points where I thought I was going to lose everything because of it, and I genuinely mean everything.
Like you, this had a knock on effect on my own mental health. Now my kid is 2 and I've gone through my own work/financial issues (team redundancies, my job relocated), a simultaneous pregnancy loss, and the general weight of carrying our family emotionally and financially for so long, I recently found myself at the point of almost complete mental breakdown. I'm now trying to get help as well. As an aside, my counsellor says that depression in partners of those with PPD is incredibly common - you aren't alone.
The good news is that, with time, my wife's mental health and our relationship returned back to normal as she returned to work and our daughter started daycare (at around 14 months for us). She's been very supportive of my own need to fix myself recently, and is almost off meds herself and happy.
I'm not writing that to show off, but to say that there is potentially light at the end of the tunnel if you are both prepared to work on yourselves and your relationship. I agree with what others have said, that the demands placed on you have been absolute BS, but where I differ maybe is assuming that those demands come from someone in their right mind. Having been through the 'partner with PPD' thing, I've seen how crazy it can drive a good person, and think there's a good chance the person you loved and fathered a child with will come back to you given time.
Whatever you decide to do, good luck. Please don't suffer in silence, whether it's seeking professional help or just ranting on here. You aren't alone. What you are going through is incredibly isolating and upsetting, but one way or another there are brighter days ahead for you.