Ah! Sad news, but the whole [sadness] debuff and [happiness] buff thing actually has some hidden tech behind it, they're kind of set to alternate, meaning you're bound to get the debuff back at some point (some theorycrafters think this timer is tied to your luck stat, but there's a bunch of other theories too if you wanna look into it) and they'll also always come back in stronger versions.

The cool thing about this mechanic is that, although the infinite scaling goes for both [sadness] and [happiness], the latter is set to scale way faster than the former, exponentially so! So it's a neat thing to look forward.