I hate to be the one to say it but it sounds like you stopped using Facebook because of the people you added. If you want to keep it for college-you don't add your Grandma or parents. I've managed to keep my friends list quite small by not adding people I meet once and never again, and by only adding a few close family members (and then using the privacy controls when sharing to only explicitly share to them when I need to). I've ignored lots of requests for family members and strangers/acquaintances and the quality of my news feed is still as good as it ever was.

Single focus social networks like Instagram are great but most people I know that use them just share that stuff out to Facebook anyway.