Knowing that you are not your moods and that your moods will pass is like base camp when you’re climbing a mountain. You still need to climb. There are lots of things you can do to help improve your mood.
I always advocate for mindfulness and meditation. Mindfulness is paying attention to your thoughts, so that you don’t accidentally cut yourself down by thinking horrible or negative things about yourself as you pass through low moods. Meditation is sitting still and actively watching your thoughts for ten or twenty minutes once or twice a day. If sitting still is too difficult then yoga, exercise, or going for walks can help to lift your spirits. Look for beauty everywhere. Notice small feelings of happiness. Spend time with people who make you feel good. Although your moods will pass, you can do things to help them pass more quickly. Happiness is not your goal, life is the goal, happiness will happen.