Combine Left/Right brake pedals to brake both wheels simultaneously

Not sure what the problem is. You seem to have pedal brakes so just press them and look straight ahead. There is no other feedback than that in a real plane either, braking a Cessna after landing requires your eyes at the end of the runway and a pedal play. At slower speeds there is no g force feedback or wind noice etc anymore that might give you feedback. You brake and then taxi with your eyes and feet.