Find something fufilling to do. A job you enjoy or some some sort of artistic passion etc.
Go for walks. Sunlight(in moderation or with sufficent protection) and exercise are fantastic for mood and health. Burn calories and get that Vitamin D which is essential for health and mood(plus can you catch more pokemon in Pogo)
And good relationships as well. Find new friends or reconnect with old friends, or someone to have a romantic/sexual relationship with. Don't feel oressured to be a social butterfly but isolation is proven again and again to be deeply unhealthy.
Eat healthier. Cut back on sugar, and excess non fibrous carbs. Eat nuts, fish, fortified cereals(stuff like cheerios not loaded with extra and veggies) whole grains, fruits and proteins. Don't try to go cold turkey on the standard fare though. Never works. Gotta wean and slowly replace vices with lesser ones.
Drink alchohol only in moderation. Avoid fruit juice. Its barely any better than soda. Plain old Water(filtered and/or boiled/purified if your local water supply is contaminated) should be the primary liquid in your diet.
If its really bad(suicidal thoughts, extreme apathy or the like) I would suggest therapy in addition.
I used to game all the time it was my passion. Now I play almost exclusively Pokemon and I have no other hobbies. ---
Hello, I like video games and comedies. Let's be friends. :)