Practice, practice, practice.
IMO, much better to train your brain to flip, than to flip the function of the controls - which seems potentially dangerous to me... you may forget that it's flipped and fly into something. And during a typical flight you'd have to be flipping back and forth often - and easy to forget which 'mode' it's in.
Find yourself a wide open space - a public ballpark, a pasture, or similar - and practice flying Figure 8s and toward yourself... you'll get it before you know it and soon enough you'll be able to do it without thinking.
edited: The one thing that helped me the most to learn intuitive stick control was buying a Ryze Tello - the king of the 'toy' drones - and flying it inside in tight spaces. In a well-lit room Tello is very stable, very responsive, and mine has survived many many crashes... I even flew it into a ceiling fan once while circling the fan, which was on and turning... no damage whatsoever, didn't even lose a prop.
BTW, do not buy a Tello without also buying the TelloFpv app (~5 USD)... a very capable, full-featured app.