Objective or relative?

One day you're feeling positive and energetic, and all those down times seem unnecessary - just holding you back, the result of all your psychological flaws intermeshing and snowballing. To be happy and motivated seems definitely the right way to be, the state you're left in when all the fog of misperception is cleared away.

The next day you're cynical and sad and all those happy times seem like a delusion, a suspension of disbelief about a world that is so obviously pointless and rife with suffering. Without chemicals in your brain to blind you, the gritty truths emerge and you realize this is the way the world really is.

How can both states seem so real at times and contrived at others? If I needed proof in the relativism of truth, here it is. If there is some kind of objective reality to the world, I can't see it through these masks of mood and perception. And since they are the only tools I have at my disposal, the reality they construct is the only one I will ever know.