For some reason my depression symptoms vary a lot based upon what circumstances or the type of mindset I am in? I guess the most consistent bits seem to be the ever constant sensation of exhaustion, anhedonia, a lack of interest in people/relationships/most things really, chronic rumination, as well as lacking motivation. I don't really feel "sad" at a conscious level unless I am faced with something that points out I am almost constantly in a low mood. I think at my worst I fall into a "woe is me" sort of mindset too, which is sort of silly and stupid.
I've been depressed for a very long time and still am not near being out of the mud, but one of the things that have helped me start to move forward is looking at the ways that I contribute to my own depression and trying to motivate myself to work on that. I'm a thinker at best and at worse and, if not forcing myself, will just ruminate on the many ways I could characterize or solve the problem rather than doing anything at all. For example, I used to have a big issue with being vaguely ascetic and hyper-self controlling, so I forced myself to do little things to counter this (ie. occasionally letting myself take breaks, grabbing a Starbucks when I didn't really deserve it, grabbing that extra piece of candy at the grocery store, maybe letting myself say some curse words, etc). It's shown a small change in my life, but small is better than nothing.