when i started not that long ago the idea of grip changes for shots seemed to be far fetched to me, that only the uber serious players did it, those who took it toooooo seriously.
But it really needs to be done. Work on a grip for your FH and a grip for your BH (assuming its one handed). You might find a less extreme grip on the BH might feel more comfortable, something like an Eastern BH.
And of course find a grip for serves, whether its conti (thats not a bad one to get used to for serve), and then its a case of practicing the grip changes during a rally and hitting so it becomes second nature.
And it does become second nature, trust me, just over time.