Yep. I know what you mean. I find myself posting silly things or whatever when my life feels like crap, and ask myself why I'm doing it. Loneliness maybe? But I keep in touch with a lot of family and old friends that way, so I hesitate to delete. Sabbaticals are nice though.
I deleted mine in October and I thought I'd feel lost without it - I spent a lot of time on FB - but honestly it's the best thing I've ever done. I likely will lose touch with some people, but the people who I really have relationships with we've found ways to stay in touch.