This is a horrible topic, but is good to see that others go through the same thing that you do, and that you are not alone.
I have battled with depression since I was around 15, and the anxiety that come with it are not the nicest. Normally I am a very happy chap, who wouldn't say boo to a goose, but then it can be like flipping a switch, and all hell breaks loose.
At present, I am far from my worse, and more often than not I wake up with a smile.
I am very lucky in the fact that my wife understands, and supports me. I have seen a doc, but he offered no help (quite typical for the ones around here), so when it gets bad, I do feel like I'm on my own.
All I can say to anyone reading this who doesn't want to talk publicly about it, is that it helps! The fog does lift, and there is always another way!
Also, as bronzee said, cutting the crap from your diet, and drinking more water does help! I'm a real a***hole when I have a big mac!