I understand how you are feeling. Would you believe that I deleted all the people that I used to talk to that are happy and content? I just have miserable people on there like me.
It is pretty pathetic all together! I know I sometimes see happy pictures with people and families but it doesn't bother me like it used to.
My only advice is just delete those people or get off facebook all together. I hate to say that "out of sight out of mind" cliche but it has worked for me. I even deleted people that I like that did nothing to me, but I don't want to see the wedding or party photos that they are "tagged" in. I don't want to see them together having fun and living a "happy" life. Or better yet a happy "facebook life" because ultimately that is what it is because we really don't know what goes on behind closed doors.
Good luck, I will hang out with you in your misery soup. I will pull up in my little tugboat and swim with you a while