ZZZ,
Sorry to hear of your ordeal.
Unfortunatley, recurrent pericarditis can be a very difficult problem to treat. Your case is particularly unusual with such a high number of recurrences. It certainly begs the question of whether or not your case is truly idiopathic, or is there an underlying cause, such as a connective tissue disorder, that is driving the attacks.
One expert here at the Cleveland Clinic uses colchicine as first line therapy for the treatment of recurrent pericarditis. He has not seen failures with this therapy, but they are certainly reported. The use of alternative immunosuppressants has been described in the medical literature, with azathioprine and cyclophosphamide being the most commonly used.
Here is a reference regarding the immunosuppressants:
TI - Immunosuppressive therapy prevents recurrent pericarditis.
AU - Marcolongo R; Russo R; Laveder F; Noventa F; Agostini C
SO - J Am Coll Cardiol 1995 Nov 1;26(5):1276-9
Hope that helps. Good luck.