Am I A Bully?

I'm being bullied by a two headed snake. My doctor suggested that I avoid the bully as much as possible due to my pre-existing health issue, PTSD. So I only converse with the bully on work related matters.

Am I wrong not to participate in personal conversations with the bully?

Am I wrong to sometimes bring a friend/co-worker in a coffee and not the bully?

Am I wrong to have stopped saying 'good morning' to the bully after the bully never replied or acknowledged me, day after day?

Am I wrong for feeling threatened by the "B"? Do I have to pretend like I like "B", because I'm not like that. That's being 'two faced', like a snake. That's not me.

Am I wrong that I speak or am friends with other co-workers that have felt "B's" raft(they're aren't many who haven't)?

Is it wrong to support one other when "B" strikes at one of us or that we've tried together to figure this problem out ourselves, unsuccessfully because the boss isn't any help.

After talking with my boss (who the bully tried to get fired) Boss seemed helpful/concerned, now just says to ignore "B". Boss just starts rolling eyes at us and says things like 'just because you don't like "B". Now "B" is accusing us of bullying! It went to HR ("B" took it) and it got thrown out. Why? Bully has history of this kind of behavior."We're familar with 'B'". We're all told to 'just let it go, ignore "B", try to get along. That was it, nothing has changed.

I'm not a mean person. I don't like to do mean things to people. I even feel bad at the thought of the bully feeling bullied by me/us. Before I started avoiding "B" I did try talking to "B", it didn't work, made things worse. I stupidly told "B" about my sickness. "B" seemed so concerned, I fell for it. Now "B" uses my PTSD triggers against me. I've had to leave work it got so bad.

I don't know how to proceed. I don't trust the bully. I shake around "B". I dream of "B". It's awful. It's controlling me.

A small example of "B". A co-worker brought me a coffee as a thank you. "B" said to worker "Where's mine? Why don't you ever bring me one?" Worker brought "B" one in the next day, told me "I was scared "B" would go after me if I didn't, it's easier this way."

Am I a bully for not bringing "B" a coffee? Did I do something wrong by adhering to my morals/standards? I've never told anyone not to talk to "B". When asked about "B" I tell co-workers, I don't have a problem with "B" and drop the subject. I do feel awful that this is going on, I can't believe I'm part of it, why, how? The work environment is toxic. How do I protect myself from "B"? And I'm really angry, hurt and confused that I might be a bully too. It makes me sick to my stomach to think I am.

So Confused.