For me, exercise was not a cure, it made me worse in lots of ways, including guilt that I didn't do it more often which made me more ill.
A few things that I did where I found literal sparks in my brain like I woke up for a bit was brain games - playing Rummikub with my parents one night. Weird 😂
Fresh flowers always out. My mum made me promise to have even a £1 bunch from Lidl every week and it always made me smile a little.
Music. Not any old music, the kind that hits you in your soul. For me that is philharmonic music and I've recently joined a philharmonic choir and we had the first concert a week ago. My god, I've not felt so good in decades. It has been unbelievable for my brain.
I'm off the sertraline after the side effects became problematic (zero, almost into minus figures levels of sex drive and finding myself unable to laugh). I am currently taking St John's Wort and have been more stable on this with less side effects for the last 3 years, but that's a discussion for your GP. I can also laugh - as in proper belly laugh - again.
Give yourself permission to laugh
Aim to laugh once a day - not a smirk, not a wry smile, try to laugh even if it's really not that funny. It's surprising what effect that has on you too.
Vitamins! Take a multi vit, bit also aim to have something fruity every day that you actually like, not eating because you should. I eat the Lidl apple sauce baby sachets because I love apple sauce 😁.
Daylight. If you can't get out into the daylight enough, I can't recommend a SAD lamp highly enough. Whilst my depression is managed, I get really really bad SAD which is as bad as my worst depression. I use the Lumie Vitamin L lamp and it quite literally has saved my life for years. I no longer get the worst symptoms of it in the winter, I don't sob every day, I don't sit staring at the wall for an hour when I get up....
I also love my job and don't worry about going to work each day. Getting out of a soul destroying job has also changed my life. I've taken a £10k paycut but it's been worth every single penny.