PickMe -
You have to remember that many come on her to vent and find support. Someone in a stable, happy relationship probably wouldn't need the support of an online forum.
I have a cousin who used to have addiction problems but is now in a happy marriage with another baby on the way. Any added stress in a relationship can make staying together hard, but that doesn't mean its impossible.
If you feel a little down by reading all the sad stories on here - maybe try reading a good book that deals with these issues that doesn't end so tragically. There's this book called "Redeeming Love" that a student recommended to me. I haven't read it yet but she told me it talks about unconditional love, and its definitely on my "to read" list.
Hope this helps.
Panther