I've posted a lot of stuff on here about Depression, so I'm not sure if there's much I can say I haven’t already said here, but I'll try.
As I'm writing this, I'm actually having one of my better days. As well as depression, anxiety and sleeping issues, I have SAD which is seasonal affective disorder. This means I get even more depressed at winter. During December it isn't too bad. I have Christmas, new years and my birthday to look forward. January is usually the worst month. Its February now though, so I'm leaving the slump a little. I probably won't start feeling better until April/May though as is usually the case with my SAD. Once that's passed all I have to worry about is watching my own emotions.
Mine are a little hard to predict. I can completely content one moment, and then with zero warning, sad the next. It can make things frustrating and I get annoyed and blame myself. Which is the absolute worst thing to do as you can guess. But that’s what depression stems from most of the time. Self-blame and self-doubt. Lack of self-esteem.
I find that last one to be particularly difficult. In most parts of my life I don't feel I have low self-esteem. Usually what happens is I make a dumb mistake, one that doesn't really bother anyone. Yet my mind escalates it to full-blown, being-fired-worthy disaster. My head does that a lot. Worries that thing will be worse than they are.
If you asking how I deal with depression my answer is pretty short: I'm stubborn. I don't take any type of pills, I did once and it ended badly (panic attacks aren't fun!). I have had a round of specialised therapy to deal with a past issue. The sleeping issues are a recent change and so I'm now being referred for CBT to see if that'll help as well. Until I start it I won't have any real opinions. My boyfriend who suffers from anxiety says its good though, so I'm positive.
Back to my answer. I'm an army brat, which probably plays a part. My dad's always been a 'get up and carry on' type. While at times that was irritating as hell cause I needed to talk, it has given me the ability to grit my teeth and endure the sad tides. I generally recognise when its starting to happen and yank myself out of bed fast. I force myself to do anything. Even if its reading a page of one book, watching a single episode and then some writing. I tend to switch chaotically from project to project when I'm down. I think when this was badly controlled it's the main reason I start so many stories I never finish.
My writing is, and always had been, a huge source of strength for me (When it isn't being my biggest weakness, but that's later). In my teens I didn't know what was going on or how to cope, so I perfected escapism. I'm pretty sure its why most people choose to imagine other worlds and people. It wasn't until I was thirteen that the idea of writing down my stories really occurred. I'd dabbled in poetry but not much. Writing remained a constant thing I could turn to when I needed distraction from my own life.
When I finished college, deciding not to go university, I was in a pretty low place. I was applying for jobs but getting no interviews. I found protag through a friend and everything changed. Having a community I could share my writing with and get feedback really helped. If you didn't guess, I want to be a published author one day. This is where my writing can be my biggest weakness at times.
I have since learnt that when I'm in a depressive sump about my writing, to stay the hell away from it. Or concentrate on a side-project I'm not too fussed about being perfect. I have no clue if any of this is helpful or not, I just kind of started ranting a little. My main piece of advice to others going through depression is basically don't give up. There's a positive, you just have to look for it.
Take enjoyment out of the mundane. Start writing lists. At the end of everyday, note 5 things that were great that day. Even if one of those is just eating ice cream or hugging a loved one. Starting a diary is useful, you start to notice the patterns of your mood dips. It wasn't until three years ago that I realised I had SAD as well. I just assumed it was always depression. Do something random as well. Dress up for absolutely no reason other than to feel good – and don't stare too hard in the mirror, you look amazing. Decide to bake a cake for no reason. If it turns out bad, oh well. Learn to shrug away the bad things and errors. They happen. As I always like to say – You're a perfectly flawed human being :)