I have problems with irritability, too...and I've not had too many good experiences with meds, so I prefer not to take them.

What's worked for me with respect to my irritability is meditation. There are many, many kinds, so do a bit of research and find one that you like. My personal favourite is vipassana meditation; it uses mindfulness techniques to help one recognize one's thoughts and feelings without judgment (and all the seminars that teach it are completely free!). Even something as simple as taking a few minutes at regular intervals to just BREATHE deeply and clear your mind can make a big difference. I feel much more centred and in control now that I do this; it helps with my anxiety, as well. I'm not big into the whole New-Age thing, but my psychiatrist recommended this to me when I told him I wanted to stop my medications and it has worked better than anything. Maybe it'll help you, too; it can't hurt to try!