If you're just looking for short term happiness (like for the day of), you could try some sort of a drug high. I'm in a depressive episode now, and I definitely feel pretty good with even a low opiod dose (actually too high of a dose can be too sedating and not happy, in my experience). Mixing opiod with benzos can be better but that seems to depend on the day for me. Taking opiods and clonazepam in the evening seems to make the next day (at least the morning) pretty reliably good.
If you don't have opiod access, you might experiment with kratom, which you can order legally online. The problem with kratom is that there are so many choices, and at least for me, the majority of them make me feel crappy. The dosage is also not necessarily straightforward, as lower doses act very different than higher doses. Usually, lower doses are more stimulating and higher doses are more sedating. If I take too high of a dose, mentally I feel terrible. My personal favorites are red bentuangie (4g), red kapuas (3g), and red sumatra (2g).
There are also stimulants, but I don't have access to any of those (I don't have any illegal drug access, all I have is what is prescribed to me), so I can't speak to them.