Diana
Kalms are more for stress but that may be causing the irritability. They are completely natural too - take a look at http://www.kalmsstress.com/
Oh look at this page - http://www.kalmsstress.com/kalms.htm
It mentions irritability.
I am not sure you can get it over there but if you fancy trying it then I am more than happy to get you some and post it to you.
Nicola