I can’t make a diagnosis on the basis of a letter, of course. However, from what you wrote, my first guess would be that your doctors are correct. The behaviors you are reporting are typical of social anxiety.
I’m more interested in supporting you in getting real treatment than in confirming a diagnosis. Cognitive-behavior therapy has been found to be very useful for managing social anxiety. There are also medications that can help you feel a little better so that you can make good use of the talk therapy.
My suggestion to you is that you stop looking at sites about mental illness and start going to a mental health counselor who can both answer your questions and can get your started on treatment to manage your distress.
I wish you well.