Here's a trick.

Let's say, hypothetically, you're feeling low and like you hate everyone, including innocent children that you brought into the world. Let's just say you think they are all stupidheads who must have been raised in a barn.

What you can do is say, (out loud, even), "I hate these stupid kids. They are ugly and stupid and loud and annoying and messy and they don't listen and I hate hate hate every bone in their bodies."

And then (here is the trick)

you just say, really super loud, "Guess what? IT'S OPPOSITE DAY!"  And then you will feel waaaaaaaay better than you just did because your neural pathways won't even know what to do with that switcharoo.(Plus opposite day is always a funny joke so you will be chuckling too.) 
And your body will be feeling all of the "I love these brilliant kids. They are adorable and bright and raucous and fun and gregarious and creative and I love love love every bone in their bodies" feelings because, guess what? You tricked your brain. Tricking your brain is called Cognitive Behavioral Therapy. It is the best possible kind of cheating.

Watch this.

I hate The Professor and I am not at all attracted to him. 

OPPOSITE DAY! (You see how that works? Because now I am going to go find him and kiss the forehead that sheaths one of the most brilliant minds of our time.)

It is always a good idea to opposite day your bad feelings. It is a back door way to count your blessings.

That's just good strategy.