I used to have the same problem when I had a FB account (always feeling anxious, stressed and extremely paranoid because of it). Finally, I decided to delete my account and, miraculously, the discomfort disappeared.
I think FB is a waste of time. If someone really wants to know how you're feeling, well, they should call or, if it's possible, visit you. FB messages are extremely impersonal and cold.
Most people don't add you not because they want to be your friends. The vast majority are just narcissistic individuals who like to post meaningless pictures and show a fake image of who they really are...something like: "look!!! my life's so perfect".
You should deactivate it for a while and see how it works. I'm not saying it'll solve all your problems, but it'll reduce your stress and anxiety.
xo