I've been there, too.
In my case it was baby #3, we were in horrible shape financially, and my lupus was out of control. Everything was wrong in our lives. The other two were 1 and 2 years old.
My mother gave me a book about another woman with a pitiful life....(religious book, Stepping Heavenward)....most of the book didn't really impress me but when the heroine was pregnant for the umpteenth time her family went ballistic. They said it all to her.."one more demand on your body. One more baby to nurse. One more mouth to feed. One more diaper to change. One more crier to listen to, one more to educate..."
and the mother, who was poor and in ill health and in a bad marriage, quietly replied, "one more warm little body to hug. One more smile for mama. One more first step, first word, first prayer. One more at the table, one more in my heart, one more comfort in my old age."
or something like that. It really spoke to me, and I began to see things differently. The pregnancy was still awful, we didn't have any more money, but "I" was different.
And God's providence was, that 3rd baby was my easiest baby. He slept well, ate well, and rewarded us with smiles and affection from day one. He's 3 now, and even strangers comment on his happy, affectionate, sparkly personality. I honestly cannot imagine the family without him, he's been a real comfort!
We're expecting #4 now, and are broke, in a little house and homeschooling. I'm feeling better now, but the first half of the pregnancy was extremely hard. Dh has been laid off for 9 months, and we might lose the house. And my lupus is flaring again. But for all I know, I'll get another little'un as precious as the other three.
I hope this doesn't sound preachy, I'm not telling you what to do. I'm trying to say I totally recognized and identified with your first post. I've been there! You'll be in my prayers, and your dh and all your children too.