I have 2 children and my wife has been diagnosed with depression. She has thoughts of suicide, and has been comitted twice. She's also on many different types of medication.
I can only wish you much strength.
I have been through a roller-coaster of emotions, some good, some bad. Lonliness is my biggest struggle, it was anger in the beginning but I read a book by the Dalai Lama who has interesting points of view on depression.
I also started a blog, a place for me to voice my feelings/thoughts. It helps, I write whatever I am feeling, sometimes just rambling.
http://ahusbandsbattle.blogspot.com/
I wish I could tell you that there is light at the end of the tunnel. All I can say is, be strong for your children, show your wife love and support, and try to find peace within yourself, so you dont find yourself falling into a sense of helplessness and despair.
"If we are overwhelmed by a sense of helplessness or depression we should grasp every opportunity to improve our situation". Dalia Lama
Best Wishes