I agree with everything that other posters have said. I just wanted to add from my own personal experience so just take from it what you like or brush it aside. A good talk with your husband is important too. He needs to know that there will be times where he will have to do a brunt of the parenting if you are having a bad patch. He has to understand this and be willing to be the primary caregiver at these times. It is a partnership and there are ups and downs just be open and honest each other and talk about things that could come up. It is better to have a strategy in place now then be blindsided and have a child to take care of. I am a planner it helps with my anxiety but I know realistically you can't plan for everything especially true for kids but I try my best so that I can roll with the punches as they say.

Sorry for the rambling. I wish you the best of luck. These are tough conversations to have but it looks like you are really thinking this through which is healthy and good.