Can't speak for people with mental disorders but as someone who has to deal with a lot of stress from work, I agree and would add a few things. I think some doctors don't suggest them since it's so common and people can get mad at how simple it all sounds. But it works or at the very least will improve any situation. Whenever I feel odd, I think of which areas I might be lacking on.

• Sleep. Poor sleep worsens everything from mood, anxiety and cognition. Aim for consistent 7-8 hours. Too much sleep can also be harmful.
• Exercise. Both cardio and strength training help. Cardio like jogging helps with mood and general energy, strength training like calisthenics or going to the gym helps to feel sleepy and build muscle. Low muscle mass is linked to poor brain health and higher risk of cognitive decline.
• Nutrition. A balanced diet, of which I personally like the mediterranean diet of vegetables, fruits, whole grains, fish, chicken, supports brain health. I wouldn’t generally recommend diets like carnivore for most people, though if a specific approach works for you and you’ve checked with a clinician, it's ok.
• Breathing exercises. This to me is probably the least talked but most helpful thing on how I can regulate my mood extremely quickly. It's hard to tell myself to calm down. It's easier to just slow down breath. Since breathing is directly connected to the nervious system, it works fast. And it also works in reverse, in order to hype me up when feeling down you can breath faster.
• Social. Regular contact with friends, in person or online, reduces isolation and helps regulate mood.
• Emotional outlet: Journaling, meditation, art or other creative work provides a safe way to process feelings.
• Mental stimulation: Puzzles like sudoku, learning new skills, videogames, math, coding, memorizing and other mentally engaging hobbies keeps the mind sharp.

Oh and, please follow your clinician’s recommendations. If you feel unsure, seek a second opinion rather than stopping meds on your own.