Should I Speak or Should I Stew?

Even fools are thought wise when they keep silent; with their mouths shut they seem intelligent. - Proverbs 17:28

Understand this, my dear brothers and sisters: You must all be quick to listen, slow to speak, and slow to get angry. - James 1:19 

Speak up for those who cannot speak for themselves; ensure justice for those being crushed. Yes, speak up for the poor and helpless, and see that they get justice. - Proverbs 31:8-9 

"Anything you eat passes through the stomach and then goes into the sewer. But the words you speak come from the heart-that's what defiles you." - Matthew 15:17-18

From what I know of the Bible it seems clear that keeping your mouth shut is usually the best response. I'd like to say that's the reason I don't speak up very often. However, there are other, far less noble reasons why I often don't say much, especially at times when I disagree with someone:

1. I'm not confident in my ability to clearly verbalize the thoughts in my head.
2. I dislike conflict.
3. What if I'm the only one who feels the way I do?
4. I have to filter through the thoughts in my head to find the ones that make sense, the ones that are beneficial to the conversation and the ones I can readily defend. By the time the filtering process is complete the conversation has usually switched topics.
5. I don't want to seem like a know-it-all because, let's face it, nobody enjoys being around a know-it-all.

So while my actions may appear to be in line with what the Bible prescribes, what's going on inside of me is not necessarily anything Holy. And that's why I find myself stewing over the things I wish I could have said.

Stewing, I've found, is like holding a grudge. The only person it bothers is me, and it drives me absolutely crazy! I will hold onto thoughts of what I wanted to say for days and weeks at a time. It can affect my attitude and the way I interact with people. At its worst, stewing distorts my view of reality so much that I start to assume things about myself, others and the world that are completely false.

So, what's the answer? I know speaking my mind is not usually the best choice. And I also know stewing over what I could have said is very unhealthy. Is there a third option?

How can I simply let go of the thoughts that seek to drive me crazy?
How do I remind myself, in the moment, that my opinion isn't really what matters?
How do I put other people ahead of myself, even when I completely disagree with the things they say or do?

In the end, I think, the example of Jesus is always a good place to look for answers. So, what did Jesus do?

(side note: Anybody remember the original WWJD bracelets? I wish I still had one. It feels like the time is right for those to make a comeback!)

This is the part where I just leave that last question out there and wait for the answer.