When I Hit A Fork In The Road

Is it possible that the things that are lacking in my life are that way simply because I'm not a big enough bitch?  Or because I tend to hesitate to say how I'm really feeling when I really should just let it out?  I just finished reading The Theory Of Opposites by Allison Winn Scotch and it got me thinking - maybe I should take the advice sprinkled throughout this novel and do something with it.  Maybe, I should start taking left turns instead of right ones.  Maybe, instead of staying within my comfort zone, sometimes painstakingly, I should venture outside of it a little more often.
I'm not saying that I'm going to morph myself into a royal bitch that no one will like.  I need to learn to stand up for myself more often.  I tend to keep my mouth shut when something is bothering me or I am being treated unfairly, whether it's at work, in relationships, or even when I know I'm getting screwed over while making some sort of financial transaction.
I've gotten a lot better at it over the last few years - I used to be a complacent doormat, I might as well face it.  Not so much anymore, but there's always room for improvement.
I can only control the present.  To an extent.  Like when I learned last week, from a fellow photographer, that apparently someone at work had an issue with the posing of my subjects and that was the reason I had been put on a few jobs as assistant and not a photographer.  The thing is - I had been doing it my way since August and nothing had been said to me.  I was so upset I nearly launched into a full blown panic attack on the job.  Ordinarily I would let it go and not bother to speak up to person I should have, the person who had the opportunity more than once to address this issue with me as I sat in their office.  But I remembered the book, and I did the opposite - I spoke up.  I called one of the supervisors (the person I needed to talk to directly was out of town,) on my way home that day and told them how upset I was that there were "issues" with my work and I was never informed, that if there was a problem, someone should have addressed it with me so I could rectify it.  I also made it a point to shoot over the two-day job to prove that I am a good photographer, tweaking the things I knew needed improvement anyway.
So yeah, ordinarily, I would have sat back and done nothing until I was approached about the situation.  But if I had done this, who knows when that would have happened.  I had to take action, especially because the integrity of my work was technically in question.  I have yet to hear any backlash, so I don't even know if I did the right thing, aside from the person I had expressed my grievance to informing me that they checked out my past work and didn't see any problems.
It's a tough call sometimes.  I'm one of those people who has a crushing fear of angering someone, whether it be a friend, a lover, a family member or an employer.  I sometimes stumble over my words, even in my head, and fear that saying whatever it is that I need to say will do more harm than good.  Past experience and the environment I grew up in contribute heavily to this.
So it's definitely time to start making the left turns when I hit a fork in the road, because I've become painfully aware that always going right hasn't really been working out for me.