I don't know what to tell you Wayfarer. When you know you're having issues due to depression then stop, relax, and take a moment for yourself. Let the whole world slip away for a while. Think about stuff that normally makes you happy or peaceful, or doing stuff you normally enjoy doing. Or even just imagine being comforted, like you're being hugged by someone you love, if that's your thing. It's not going to make anything just magically go away, but it helps. Well, I mean it helps me sometimes. I don't know if it works for everyone.
Actually, for the longest time I think I dealt with depression by having some imaginary friends. Imaginary worlds, even. Places I would escape to in my mind and I kind of 'lived' there, in a way.
Also, I'm not sure if everyone knows this or not, but having a routine/schedule for your days supposedly helps to alleviate symptoms of emotional disorders, like depression and bipolar. Wake up the same time every day, go to sleep the same time every night, eat breakfast, lunch, and dinner and try to eat around the same times every day. Drink only water or fruit juices, too.
Honestly I don't know if that works or not. I've never once been able to keep a schedule my entire life. But it is what some professionals suggest you do.