Unfortunately, for many of us, Facebook is most of our social life

Personally, about 90% of my friends are online and I chat with them either via social media or online gaming and I know a lot of people who are in a similar situation so telling the OP to delete Facebook or to not make it a big deal is easier said than done because many people find it difficult to simply go out and socialize and make friends the old school way.

Do what I'm doing and take a hiatus from Facebook until your mental state improves. Get those you want to deal with on Facebook to add you to Skype or email and take a break from everybody else