After having my girl for several years she become very irritable and out of control. She even attacked a friend's dog. It ended up she was diabetic. She is now on insulin. Now when she get irritable I know her glucose is out of control again and off to vet to adjust her dose. You really need to rule out all possible medical issues.
If it isn't medical you might want to look at other option. It might be a little weird to some people but I have had a lot of luck with pet communicator with different pets over the years. It can help, just make sure you find a good one.
Check out web site for someone I used in the past http://www.petcommunicator.com/