You are more than likely over-gripping it.
Hold it like a raw egg. Don't drop it - Don't crush it.
It will NOT fly out of your hand.
Then, practice trigger control by dry-firing... lots, till you can dry-fire it aimed at a spot w/o twitching or wiggling the Bbl.
Then go out and shoot it.
(and then practice dry-firing again... some more... lots...)