It took me years of practice to stop before I blew, and even then I still occassionally blow it. There are times when my mind just flicks a switch and I am off to the races whether I want it or not.
I am surprised your parents don't know your diagnoses. That seems a little odd to me, but that is your life, not mine. I know once my parents knew what was wrong with me and they started to learn about it my bizarre behavior got more understandable.
How did I learn to control the blowouts, practice with friends and therapist. I would role play. I always felt like an idiot when I did it, but it payed off well later when I was in the middle of a tense situation.
It took a long time and lots of practice before It started working in real life situations though. I am not about to tell you it happened overnight.
I wish you the best. Keepposting.