Consider TEST your support group! Watching funny vids is good, but when a solid depression sets in, it's not quite enough. I find that getting some sun during these bleak times of minimal daylight helps a lot (and I should probably take some vitamin D as well [insert joke about wanting the D]).
Fantastic that you have a goal or achievement to strive for - that's probably one of the very best things you can do, as it gives you a focus and purpose to keep in mind. Think ahead - what will be the next certification you go for after the S212 cert?
Plus, feel free to jump onto Discord and just vent - no matter what you're going through, it's almost certain that another TESTie has been through similar crap and can totally relate. In fact, I'm downright amazed at how tough and resilient my fellow TEST members are - many have endured great hardships, some on a perpetual daily basis. "When life gives you lemons, make lemonade" is how the saying goes, but that doesn't seem to fit the resolve and constitution of my fellow TESTies - for them, the maxim is "When life gives you lemons, make the lemons your bitch."