I've always been a bit of an optimist, I guess, despite certain doleful leanings. Or maybe I'm naturally dismal and use optimism as a way to keep moving forward. Either way, I've gotten in the habit of looking on the upside of any situation.
In the middle of a renovation, when I can't find my toothbrush and fixing a meal consists of pulling random bits of food out of the fridge and calling it dinner (because, of course, we can never afford to eat out when we're renovating), I can cheer myself up enormously by remembering that at least I have an excuse for not doing the dusting or vacuuming.
Not that I actually do it when we aren't renovating, but you get the idea.
If, by crazy chance, I do find myself with a duster in my hand, I think, "Well, at least we're not renovating."
The key to making this work for you is to contrast the very worst of situation A to the very best of the situation you currently find yourself in.
If, for example, while walking to work through the freezing cold this morning, I had compared it to my usual state in February while self-unemployed, that is, sound asleep and warm in my comfy, comfy bed, the tears would have turned into icicles on my chin.
Instead, I remembered how much worse it feels to wake up at three in the morning, wondering how the hell we're going to pay the mortgage this month.
Compared to that feeling, the unfit-for-human-habitation cold barely registered.