I know that it is hard to leave—“I have to be there because that’s where all my friends are!”—but it you stay there and you keep contributing to it, then you are part of what enables it to keep going. You are part of the problem.
It doesn’t have to be an all-or-nothing thing. Keep your account if you feel you need to, but don’t post stuff. Don’t comment on posts you see. If you have the need to post your thoughts and opinions and stuff you find interesting, find another place to do it and point people there from Facebook. Is it more work? Sure. Will fewer people comment and give you likes? Probably, but if that possibility bothers you enough to keep you on Facebook, then maybe you don’t hate it all that much.