Mental health is a tricky subject. While most people understand the basics, every person feels and reacts differently depending on their condition and life in general. Personally, I have unipolar depression (basically, 'regular' depression as opposed to bipolar depression that involves manic phases as well). I have found many ways to cope with my mental health and find ways to feel happier more often, but that doesn't mean I'm cured or just always happy.
When life starts to get stressful, or I just don't like how things have been for a while, I get pulled back under the wave of depression and it is hard to get back out. Sometimes, the best thing for me is to give in to the fatigue, limit my 'necessary' responsibilities (does the shower really need to be scrubbed today, or can it wait till this weekend?), and focus on me for a couple of days. If after two or three days of sleeping in my free time and trying to limit what I do in the day nothing has changed, I'll go to a friend and try and talk out what's been going on.
I am a busy bee type of person, so usually if I'm not going 90 miles a minute most of the day my friends notice and ask me what's up. I think that is a big part of why I have had more good weeks than bad ones this year; I have the best support system. I send signals I don't even notice when I start to need help and my support system has laser goggles to spot ever misplaced hair when I start slipping again. To all of you, thank you. I hope I help you all feel as comfortable and happy as you make me.
At the end of the day, the important thing to remember is when you do slip into the dark, it is all chemicals. Try to not let it consume you, but do listen to your brain and your body. If you need to sleep all day for a couple of days, take that time to rest your body and mind! Never be afraid to ask for help either, a support system is there to support you. If you feel you have no support, try going online! There are services with text, call, and email of people who want nothing more than to help you, as well as facebook groups made with the intention of helping as many people and creating a web of support to catch you when you fall!