I have never experienced true dark times, just typical anxiety of growing up and becoming an adult (which in hindsight are nothing in the grand scheme of life). But, the 3 things that I love and look forward to are working out (ok, I dread this, but I love the results and the post workout feel), cooking/eating, and watching new and old movies.
I work out 5-6 times a week, and coupled with a healthier diet and not travelling as much have cut down to 180 (I am 6'1) from 210 in about a 15 month span. From when I started working out (2015) I am down from 227. This just naturally gets me to feel better, even if I am already happy.
I cook all the meals at our house. I have a spreadsheet to plan meals which also helps with binge and overeating, but also allows me to plan meals in advance a few days. I will get pumped, look up creative ways to alter a spice or sauce or whatever, go do the shopping for it, and then make it. It is a lot of fun to find a new meal that is delicious. Also love going to restaurants but don't get out as much with kids.
Lastly, I love film. So if you aren't into movies, this probably wont help. But maybe another hobby that doesn't "run out". I will run thru directors filmography's in order, binge an entire years of best pictures in a week, watch all nominated performances of an actor/actress, etc. Just creative ways to watch movies again and again. Then I will typically see all Best Picture nominations in a given year in theaters (or streaming if they are there first). I think I probably average about 25 movies a year in theater. I will also couple rewatches with podcasts (The Big Pic, Blank Check, Rewatchables) which makes the podcast more fun.