Schedule dates and outings. Have fun with your friends. Don't hog the conversation by talking about your problems all the time. Take the time to listen to them, too. Enjoy the companionship of your friends and don't forget to laugh and have fun.
Laughter reduces stress.
If you lack friends, or desire more friends, make an effort to meet new people. Join a club that involves an activity you like to do, such as a bicycling group or a book club. Take a class in something that interests you such as calligraphy, communication, or aerobics. Make an effort to smile at people. Strike up conversations.