Hi dear. If all these problems are there for more than weeks then it may be part of depression. In depression difficulties in getting concentration, forgetfulness irritability are common. Along with that person experience low mood, weakness, interaction with other decreases, have lost interest in previous pleasurable activities and had pessimistic thought about future. it's not necessary that all these symptoms have to be present but some of them may be. Along with that disturbed sleep and appetite is also changed. If you think so please visit a psychiatrist for proper evaluation. Even then if you don't have depression still I advice you to see a psychiatrist. He definitely help you.