I don't have any kids, so I don't have any experience with parenthood. But I did notice something in your post that I wanted to mention in case it helps at all.

It sounds to me like you're trying to pick the lesser of two bad options, which is hard to do and never feels good no matter how long you think about it and which option you pick.

Sad questions don't have happy answers.

It's kind of the idea of thinking about how to "not lose" versus thinking about how to "win."

So maybe ask a different question instead. Maybe ask, "What if I can have whatever I want out of life? If I could author the coolest most fulfilling happiest winning story of a life for myself, what would I write?"

Find all the beauty and excitement and joy in a life where you have a child.

And then find all the beauty and excitement and joy in a life where you and your husband (congrats on that engagement =) opt out of parenthood.

Really really think about it. Flesh it out in your mind.

These scenarios are just as a valid as the scary ones where everything goes wrong no matter what you choose. So err on the side of good instead of bad.

When you do, you'll be picking between two beautiful joyful exciting options. And it might still be a difficult decision, but it's going to feel a lot different. It will be difficult for a better reason.

Take losing off the table. You don't have to accept losing as an option. And forget about everyone else, and forget about the world. The great majority of our experience of life is based on what we are thinking in our own mind. If you want a kid, and a happy marriage, and to be rested and happy and healthy, then create it and take it. Settle for absolutely nothing less.