I have come to the conclusion that it's impossible to leave Fecebook altogether if one has family and friends that are pretty much FB-only types. These days FB-only types are legion, too. You may send them a regular email; they will answer it on FB. You may call and tell them you've been worried at not hearing from them; they will tell you they've "facebooked" you, as if that's a verb.
In short, once you go FB you can't go back.
And so, in order to maintain both connections and sanity, I limit FB exposure. Once or twice a day I'll go check- scan the "home" page, read the messages and my "wall". There are always memes to post, news to share, funnies. There are some FB pages that are just hilarious- "Awkward Bands and Musician Photos" has brought me to tears several times- and some that are informative, and some that are rather like a group meeting. I can too easily be drawn into the drama of the moment, so I avoid tsuris and breastbeaters. I don't lurk. I avoid commenting.
And most of all, I don't even try to keep up with everyone anymore. I think that's where the trouble comes from. There's too much going on, you just can't read everyone's page, comments and "shares". I figure if it's important enough it'll be brought to my attention. I don't need to see today's cat photo funnies (and ever since reading how a lot of them are done, with dead animals, it's taken the ha-ha away) or angst-ridden Hallmarkish quotes. But I do like the news (it really is the best way to get local news around here) and seeing friends' photos.
FB is something you can work out for your own means. For some, it fills their days. They're there anytime you log in, day or night, and ready to argue. I can't do that. It has its place in my life because I can't be in contact with some people any other way. That's how it'll stay. But as a steady diet, like sweets and chips, it's bad for you.