PTSD and Depression

My wonderful partner and I want to get pregnant. He’s super helpful with helping me manage my symptoms (I’ve had an extensive history of abuse of all forms) but I can’t help but feel that I wouldn’t be a fit mother because of my difficulties with my mental health. Anyone else feel this way?? I’m so scared that I’ll dissociate especially if I experience post partum depression. How can I be a good mother if I am so prone to checking out? I’m scared and while he helps I don’t think there’s any way he will ever understand that fear.