Hi Blue, yes I have felt feelings of irritability or anger, and negativity. I'm usually a happy person so when I get in those funks I attribute it to hormones and/or a bit of depression. If I keep my feelings inside, which I know doesn't help, I'm not as bothered by feeling anger, but if I get short with someone, or speak in a negative way I get very upset because I hate to hurt anyone I love (or anyone else for that matter).
The best way to stop being that way is first, recognize it (which you already have), and then just don't do it. It's simple really...sometimes with anger lashing out (with harsh words) is almost impulsive, but before you say something you'll regret, step back and think first, it's always never worth it.
Negativity is no fun either...try to thing of things in terms of gratitude...instead of looking at the down side of a situation always look for that silver lining, sometimes it takes a little creativity, but with practice you can find something positive in anything.
Take care :)