You have been suffering from these problems since when as it is necessary to if this is your way of seeing issues and reacting to them. Anxiety might be due to many things such as fear of underperforming, fear of failure, anticipation of going things wrong, creating problems in your mind which are not there, comparing yourself with others and always expecting positive results. Anxiety leads to loss of concentration and sets in early frustration. Anxious mind always tries to so things in hurry and expects nothing bad happens, but in reality reverse happens and we are not able to handle it. This become an vicious cycle.