Don't feel bad about people not acknowledging your pets' deaths. Probably most aren't into pets the way we are. The loss of our pets hit us as hard as if it was family, if you aren't a real animal person then it doesn't mean that much. I have a lot of friends that are as crazy about their dogs as I am about mine so when something happens to one of us we can all relate and share our feelings. Then I have friends who are not animal lovers so when I'm with them we just don't talk about pets. I really don't expect them to go out of their way to express anything if I lose a pet, they probably have no clue , I just spend more time with the friends who are pet lovers like I am.
As for Facebook, I would never join that, just isn't my cup of tea and yes, I heard a lot of people talk about it in negative ways. None of my friends are n there either. Seems like maybe you hitched up with the wrong crowd, maybe ditching facebook was the best thing to do. Try getting together with somne real life friends, people you can visit and go places with without FB.
As for the nasty friend-- there's one in every crowd, they eventually fade away when people catch on.