Hi there, this must be very scary for you.
My son had a routine Echo recently as he needs a kidney transplant, and they found a very small hole in his heart, so small that they didn't bother to tell me when he was first born and he had his first echo! I have been told it will close by itself and apparently it is very common, about a quarter of people have them, and they close on their own.
I hope things go ok for you and it closes up by itself x