It is very disabling to have social anxiety which leads to poor performance socially and professionally, many people are not aware that it is a treatable problem, there is effective treatment for this problem . Great u have identified your problem it is time to step out and seek help.

Dear sir, Please realise that you are suffering from a common problem which does have a fantastic solution too. You have symptoms of depression and anxiety disorders in a combination of one facilitating the other. The best thing for you to do would be to meet a psychiatrist and get yourself assessed thoroughly. Once that is done, your treatment can be elaborately planned and carried out for best results. TREATMENT IS POSSIBLE.

You are already successful by writing in this forum. You have gained a great confidence to appeal here. May be due to some childhood pattern you could have developed those behaviours.  Don't worry.  Do consult a professional in your city and learn to come out of this issue at the earliest. You might wonder about yourself  later.