Feeling low every time. Even everywhere!

I fear taking to strangers even though they are my friends relatives or friends.i am tensed especially when i go to sleep and when i wake up .as a fresher in an it company i dont understand what to do at work i fear asking doubts.my heart beat fast when the team lead ask for something.i am having low intrest in every daily activities.i am going to office just because i dont have leav.i am not having intrest in talking to friends on phone.i don't take unknown numbers call. low intrest in talking actually my friends are fed up with my tension in office so i can't talk to them on it any more.i thought of quiting the job but my financial condition doesn't allow me to do so.i also can't concentrate on work.i fear everything in office except the close 3 people.every one says that i am having a very low energy in office and even everywhere