The Monster at the End of this Day

As many of you know, I've had a tough run in my work life this last little while. It all started when I worked at the shady auction house. Here's a quick recap. The boss a the shady auction house was one of those people who should never be any one's boss, he had to assign personal blame for every tiny thing that went wrong, which led to a witch hunt every single day in the office. People weren't even concerned with doing their jobs properly there, they were just concerned with ducking blame. I was regularly scapegoated there, and I would get called in for these meetings with my supervisor which, had I been watching it happen to someone else, would have been hilarious. How could one low level employee possibly have the power to fuck up so much stuff? Here's one example: I used to generate their auction catalogues, from data entry to printing, but I'd be typing up stuff that i had no idea about, big machinery from factories with names that were mostly numbers. And so, the auctioneer, who knew what the stuff was, would have to sign the proof before I sent it out to be printed. Once (and I did about 30 or 40 of these catalogues in the few short months I worked there) we had a mistake in the auction catalogue and they blamed me for it even though the catalogue that came back from the printer was the exact same as the proof the auctioneer had signed, so he, who should have known, missed the mistake as well. So my boss calls me into her office and asks me what I think I could do to avoid this problem in the future. I had to bite my tongue from sarcastically saying, 'Maybe we could have some kind of checks and balances thing where the auctioneer could check the proof and sign off on it before it went to the printer - oh no wait - we already have that in place!'
After I left that job, I couldn't work for months. My agency would call me and offer me work and I'd get cold sweats and start tearing up and I'd have to tell them I wasn't ready to go back to work. Once, I agreed to go back to work, thinking that I could just ignore the panic and I had to call them back and tell them that I couldn't do it after all.
So, as you can imagine, now that I'm back at work, when I get asked to go see the boss in her office, it makes me want to quit on the spot and go home and hide under my covers. And that's what's happening today, the boss asked me for a meeting at 4pm on a Friday afternoon, anyone who has ever worked in a crappy office knows exactly what a meeting at the end of the day on Friday means - it means they watch you clean your desk out and walk you to the elevator and take your pass key. Or, that's where my mind goes when I hear that.

Here's what's been happening at work over the last few weeks....
One of the people who works here, let's call her the 'troll,' has been complaining about me and my counterpart, let's call her my 'little buddy.'
The whole thing thing started when my 'little buddy,' who is really good at her job and a lovely person, got a call from an angry guy who couldn't get in touch with the 'troll.' He claimed he left the 'troll' a bunch of messages and she'd never get back to him, and he wanted to talk to her supervisor. Now, I'd rather not have to put a call through to some one's supervisor, but if they are insistent, then that's how it's got to be. It's not our job to screen those kinds of calls. The 'troll' found out what happened and yelled at my 'little buddy,' gestures with her finger, and then when my 'little buddy' was about to tell her side of the story, the 'troll' stalks off. I came back to our desk shortly after, and my 'little buddy' looked shocked. In the next few days, I imagined that the 'troll' would come back and apologize for her outburst and smooth things over, but instead the situation just got worse. She stops speaking to both of us.
A few days later, a person comes in for a job interview a half-hour early. I call the 'troll' to tell her. Sometimes, if someone comes early, they do the meeting early and everyone is happy. Well, I get the 'troll' on the phone and she yells at me that the meeting isn't for half an hour and hangs up. So I'm shocked. And, I forget to ask the lady who's there for the meeting to hang up her coat or anything. The 'troll' comes out, after making her wait for half an hour and starts loudly telling the woman that "we" should have asked her to take her coat. Like the woman cares, and really, if you made her wait half an hour, do you really care about her comfort?
So the boss comes to talk to me. I explain my side, the boss says that the 'troll' complained and that she just wanted to check that I knew to ask for coats and hang them up. Duh! I quietly point out that the 'troll' is being unprofessional and that I can take it but I feel that the situation was pretty unfair to my 'little buddy' who is only filling in for a month.
At this point, I'm having shady auction house flashbacks. And I start avoiding the 'troll' more and more.
Then, another few days later, the 'troll' comes by my desk at the end of the day and I'm chatting with our accounts payable lady while she's waiting to meet someone by my desk. The 'troll' has the balls to ask me to help her with some collating or something. Now, I'm not an office diva, if something needs doing, and I'm on the clock, then I'll do it, no matter what it is. I'll pick up your dry cleaning, get coffee, take your car to the mechanic's, I don't care, it doesn't bruise my ego. But the 'troll' was interrupting a conversation, which is fine, but we both took a moment to acknowledge her, and, in that, time the 'troll' took off. And stormed into my boss' supervisor's office and started yelling that I was unhelpful, and that we look down on her and think she's incompetent and the boss mentioned that the 'troll' had complained about us "multiple" times.
The 'troll' is quite high up in a pretty big organization, I've worked here for two months in an entry level position and I'm still on probation. Does it really matter to anyone here what I think of her?
The number of times I've been called into the boss' office to talk about this when I'm already nervous about such things... is starting to grind me down and this chick refuses to come and smooth it over. I asked my boss' supervisor to convince her to come and talk to me.
I'm on probation and my counterpart is a contract worker, so we're not exactly in a position to make demands here. So, once again, this whole thing is ruining my day.
Wish me luck when 4pm rolls around.