Hi, these are sign of depression. In depression irritability is common. Person get irritate on trivial issues. Along with that also have other problems like sadness of mood or low feeling, decreased interests in pleasurable activities, weakness in body, impaired sleep, impaired appetite, pessimistic thought about future disturbed personal and social life. Any of above symptoms can be present and it's not necessary to have all these symptoms. Finally if you think that you are not as of previous self or found to be changed or your family members or friend say so then please see a psychiatrist. He would definitely help you.