Keeping my head down

For someone as vocal as I usually am, it is very difficult sometimes to keep my head down and my mouth shut. I just get frustrated with people and it is honestly all that I can do not to just break it down and tell them how the cow ate the cabbage. I can't be too specific or anything, but let's just say that sometimes I fail miserably at keeping the verbal censors well tuned. What I'm upset about right now is one of those things I have no control over and letting my "nu-uh, you're not getting away with that crap" flag fly will just risk some good things that I have. So, I'm left with nothing to do but bite my tongue, vent a lot to my poor husband, and post cryptic things on my blog! ;) Surely someone knows what I'm talking about though, you know, when it physically hurts to keep your mouth shut?!