It's really hard. I had postnatal anxiety that developed into depression with my first baby. I'm taking low dose sertraline which has helped me not have such a negative outlook. Along with this I had some therapy to challenge why I thought I was always to blame and didn't deserve the same kindness and consideration than others. It's been so good for me, not only as a mum but in general to help me not feel like I'm inadequate generally. I'm ace 😊. I hope you can get some help if that's what you'd like. I used a book called self compassion as a start which is good.
Yes I had it after my 2nd and now 3rd baby. I’m about to start fluoxetine for low mood & anxiety and I also self referred to NHS talking therapies. Have a google there should be a service like this in your area
I found just reminding my self helped about how well I’ve done so far it’s nothing you have done your smashing it and the feeling comes and goes for me every so often