I've included it because the writers intense dilemma leapt from the page. Her feelings reminded me of my wifes experience with depression. As such, I felt compelled to mention in my comment that she may, just may be experiencing a brush of post-natal depression and getting more info. and a qualified opinion could be an idea and help ease her obvious pain; bravely written for all to see. The site in the link is one of a few I follow on Twitter.
I'm including some other links for anyone seeking information on depression and its various forms; post natal, post partum and many others. These are comprehensive sites dedicated to assisting those with depression. We didn't know of these sites when depression hit our family. We weren't on the net. Depression sufferers are not alone despite feeling that way.
In Australia you can go to: www.beyondblue.org.au, www.youthbeyondblue.com for young people if more appropriate. I haven't looked around these sites much but they look good and comprehensive.
Another site (USA) I think; www.postpartumprogress.com has lots of helpful stuff. I'm including another link for this site to a particular article written by a therapist about treatment of depression. It's pretty good in my books; http://www.postpartumprogress.com/weblog/2010/12/postpartum-depression-recovery-a-therapists-perspective.html
There is a lot of information and down to earth help on these sites. It may also be a little overwhelming or just too hard to do for someone with depression; I know that it can be that way. If that is the case, see if you can have someone you trust, help with some exploring. To read just one article that goes close to how you feel, might help just a little.