really All the statements you said are right . but most seem optimistic and theorical , i think.
i have somehow the same problem in somewhat exaggerated manner . when i enter a completely new situation , like the day i entered university and as i remember the first day i entered school , the first day i get into a bank to pay a cheque , go to a shop lonely and like these , i have had an overwhelming anxiety that completely takes my management and improvisation power. and i never could overcome the situation in these times and so i have always chosen "not involving" in these situation as i can .in spite of what Colm OReilly said , i think that this "sympathetic" anxiety is never constructive and benfical in human functionality. because it takes over , it takes concentration and judgment power and as this is bad feeling , it "can" lead to avoidance from safe new experiences. i dont see any "evolutional" philosophy for it.
i have sought psychiatric help about this but doctors never speak hopefully about treating this by medication.
i really, really , understand you.
this is purely unconscious procedure , so dont try to act it by philosophy and reasoning. but if what rene_stpierre said , "forcing to involve and experience and not to skip and avoid in a long-term excercise" does work , and one can learn this confidence , then this is the lone way , and you should go through it. it seems promising and practical.