I don’t know the answer, but I can write some things that often help me:
- Get away from social media, movies/tv/games, and the news for a while (3-7+ days). I don’t really use any social media except some YouTube, but I stop that if I am getting too overwhelmed. Too much computer/phone time, and especially too much social media, can be unhealthy. (See also Digital Minimalism: "Why We'll Look Back at Our Smartphones Like Cigarettes" and digital-minimalism )
- Get enough exercise. I walk a lot — anywhere from 10 to 60+ miles per week. Even a brisk two mile walk can be helpful. If there is another kind of exercise you like, that could work too. For other ideas that don’t require equipment, look up busydad training and Mark Lauren on YouTube.
- Get out into nature. If you live in a city, there are probably some parks around.
- Eat well. If I don’t eat healthily, it starts to catch up with me. If you don’t know how to cook, then that could be a new hobby to investigate. I’m often in a rush, so I try to plan out healthy things that are easy to make in advance.
- Read a book. A good book can pull you out of habitual ways of thinking and see things differently. There are many books on self-help, motivation, and productivity that might spark inspiration. Also check out The Great Courses on Audible and free lectures on YouTube for ideas.
- Get enough sleep. My brain doesn’t function well if I don’t do that. The walking during the day helps me sleep better.
- Take up a new hobby. If you aren’t sure of what to do or how to get started, browse around sites like Skillshare and Udemy for ideas. E.g., art, music, languages, writing.
- If you play an instrument, try picking it up for at least 15 to 30 minutes per day. For me, picking up my guitar often quickly solves a mood problem.
- If your mood tends to swing up and down during the day, it might help to keep a journal. Make a mental note of when your mood changes, and write down what might have changed your mood. After a while, patterns will appear. When the mind gets into a negative mood, it’s often hard for the mind to see what happened from an outside perspective, but if you write it down, you can start to see what is going on from an outside perspective when you go back and read it later.
If you’re feeling like your negative mood is a serious problem, it might be worth looking into getting some help with it. If you’re at school, there might be a counselor who could offer assistance.