honey, you are not alone! I have suffered 2 major depressions in my 31 years, the most recent after the birth of my 3rd child. The important thing is to get help and to talk about it to people who care about you. I found excercise (especially walking in the sunshine) to help, as did anti-depressents.
I think in my experience that once you recognise what's been going on, that is the turning point, because then you can start treatment and work your way up out of the deep dark hole that you've been living in. So well done, you're on the way up!!
Good luck I wish you happiness!