Hello, irritability can be a counted for in more than one way- as a personality trait, as a manifestation of ongoing stress, depression or anxiety, as a secondary complication of an ongoing relationship difficulty or work pressure, effect of substance use ( alcohol, smoking), secondary to insomnia or poor physical health. Having said that, it's only logical to first  find out the actual cause of the same for a holistic management plan rather than attempting to help your own self without professional guidance.