mistral - I appreciate your advice, however, in my situation it would not work as there is only 1 person above my boss in the entire organization and she is the Director General (consider her like the CEO).
My boss is VERY high up in the hierarchy. He is the Director of Public Relations and Communications for our entire Government Department. In fact, I heard that the Director of Human Resources even complained against him to his boss, but nothing came of it. Absolutely nothing. Everyone hates him. He has no respect amongst the Directors from all the other business units - they all know he is screwed in the head, but because they don't work as closely with him on a daily basis like I do, I guess it doesn't affect them as much, so they just sort of tolerate him when they have to deal with him (plus they are not in a subordinate position like me).
He is a total slime ball. I can't go to his boss, because she won't do much. She is way too busy to deal with a complaint from me. As bad as this situation is, to her it will seem petty - this I know.
Also, like I said before, if I complain against him, it will be a CLM (career limiting move) or worse CEM (career ending move).
Oh gosh... your story sounds just like mine a few years ago. I had started this job where my manager was a complete jerk. He was rude, over demanding and demeaning to the point that for the first time in life i started getting worried about work stuff when i would be at home. Infact I remember that i was so stressed out that i woke up on a saturday morning and dressed up without realizing it was not a work day lol...
The only ray of hope for me was that it was a developmental rotation for me for four months, so i knew that in due time i would be out of there and just like your situation, i felt that my taking action against him would not be seen well in the company, although i know there are a number of places i could have taken my grievance against him as the company is pretty big on workplace harrasement and code of conducts. (Btw, you should also know, this sort of behaviour falls under harrassement, and by law your employer is to investigate the issue and accomodate you). I did give my HR coordinator some inklings that things were not going too smoothly in this assignment. On various occasions, i would be called into his office and loaded with unrealistic amounts of work and deadlines and he would follow up on that a minute after the deadline passed. It was like working under a nazi. I took all of that crap because whatever his behaviour was to me was in person. However, about 7th week into it, he came and insulted me in front of other employees for not having followed up on something he wanted to do. That is when i lost it too; i didnt think of any career or job stuff, i gave him a piece of my mind right back in front of everyone... I told him to deal with me in a professional manner, that i am not his personal servant and that i was going to report this to the HR and that is exactly what i did.
I told the office HR that i was being unnecessarily pressured into signing things without due analysis and that is against our code of conducts. I was right away assigned to another section (good riddance!) while they did a disciplinary action against the manager and ultimately gave him a warning. I went on to a better job as a result of this and none of this has affected my position in the company in any manner at all... Infact, those poor guys still working under that guy thank me for having done that and now he is more cautious with dealing with everyone there... The company let that jerk operate because he was seemingly producing great results and no one ever complained against him so he had a great record... Once i complained, other employees were asked about his behaviour and the HR people were so surprised that no one ever brought it to them...
So anyhow, just like you, i was scared of not doing anything because it would affect my career, but trust me not doing anything about what bothers you at work is the worst you can do for your career. These kind of people pass their stress on to others and reap on the benefits, without giving any credit or recognition. Ultimately, you will end up doing all the work too and not be anyone's star for it.
My suggestion to you is that first you educate yourself on your rights, since you said you are in a unionized company (like mine), there must be a variety of avenues to take your grievance to in a confidential manner. First place in my opinion is your union rep who is usually just an employee like yourself and who can guide you in workplace rules and regulations. Then, if you feel you can resolve the matter amicably, talk to your boss and tell him that you have now come to a point where you cant carry on like this, and either he lets up or you will have to go for your rights. And if he agrees to lessen your workload, but you see any visible change in his attitude at you, do go to your HR rep and tell them. Once an official complaint is made, they are legally bound to ensure that you are protected and nothing is held against you in the future for this. After my incident, i heard of some family friend in the US fed govt who was passed over for promotion and he sued them and ultimately they promoted him... and has been getting promotions ever since...
So stop crying and stand up and fight for it! All the best!