Everyone is different. My friend says I have a Quentin Tarantino way of thinking. I hold expectations and place value into things that I can’t let go. I always need to find affirmation, seeking for the answer I’m looking for even after being given. If you can afford professional help, go for it. May people here have already said exercising, diet, and correct rest. All of these are key things but A part from that is attainable goals. Goals allow you to find small outlets of happiness. Achievements that you are happy to do. I put my mind to something and I stick to it until I’m able to do it, sometimes it backfires and I get depressed because I can’t But I find something else to focus on. Lastly I went on a 14 day meditation learning how to let go of everything and being able to equalize all things good and bad on the same level. It’s called Vipassana, it is offered in many states and countries for free, you don’t speak for 12 days, they feed you vegan and vegetarian and you follow a schedule from 4-9 of mediation rest and learning to let go.