Did you check the orientation of the flight controller. When connected to betaflight and you tilt your quad forward, does the 3D model show the same motion? If that is correct, the other option could be on your radio.
The best way to test is to arm your quad and apply slight throttle so that the quad does not take off. Then move your pithc stick forward, back, left, right and your quad should slowly tilt to that direction. If not then you need to check you dont have any mixing going on your radio, or go to betaflight to the receiver tab, and make sure that none of the channels are reversed.
Hope that helps