Facebook is a source of much stress, as people are spending so much time on it, reading and being offended by other people's posts. A good way to start to have less stress on Facebook is to unfriend all the "friends" you have, and only keep close family and friends. In fact, if your close friends and family are the source of your stress, then you may consider unfriending those family and close friends as well. By only keeping positive and close people as Facebook friends, you can then build on the caring and positive support group you need, as you are obviously in distress from all your time on Facebook. But the stress is not neccessarily about Facebook, but rather the people you interact with while online. By unfriending "friends" and negative people, then you don't have to expose yourself to all the petty statements and judgements made by people who are not worth your time anyways.
Technology was meant to enhance your life, not worsen it. Do yourself a favor and start unfriending your Facebook "friends."