Since I adopted my 'monkey mantra' of hear no gossip, see no gossip, speak no gossip, ignore all gossip, rise above all gossip (etc etc) life has been much easier. For me it wasn't in the office but amongst mummy friendship groups (so glad I'm working again now!) but I think the same rule can apply.
You do need to develop a polite calm manner, one that clearly shows others that you are not playing their game. Sometimes a little passive aggression can work wonders too. When a colleague is being rude, calmy and sweetly say as Kiwi says, or even "look, you're obviously rather annoyed about this, leave it with me and I'll look into it, come back in ten minutes when you've calmed down and we'll discuss it further".
It doesn't matter who it is who's making your life a misery, there are tactics you can develop to make yourself less of an easy target. (Not that this is your fault at all). You may still feel upset on the inside, but you have to work on looking confident externally, you know how there's always one person in an office who seems to generate respect, who the office knobber never picks on? Watch them, see how they behave.
Its a bit of a game, a dance, all is not lost. Friendships are great in the work place but they're not essential. Good luck.