Facebook's primary aim is to get you to stay so keeping your attention is key to getting you to look at more ads. You feel depressed by looking at other people's Facebook webpages which look positive and happy so you compare it to you own sad, miserable life. Reality is folk mostly post positive reinforcing stories, not the crap in their lives that you'd miss otherwise. The best way to deal with social media is to stop using it completely. Life is too short to waste your precious minutes on this planet using Facebook.