Dear Gharel .. it is not a unique problem many people have this feeling for many reasons when they start a new work .. you just smile and think positive and trust in your abilities .. best wishes .
You first need to find out what is causing anxiety in you. There may be a lot of reasons to it. After that find a perfect way to deal with it. Start socializing with people's around you or join a certain activity classes to relive your anxiety. If nothing helps then visit a counselor.
Always think at the positives more then the negatives, and do things that make you happy. And also will power and at-least alternatives is professional medical treatment is need to prevent the anxiety. But About my opinion Always be happy is the best medicine of anxiety.