Bearing

Bearing (noun) the manner in which one conducts or carries oneself, including posture and gestures

Source: TTTC page 171. No sense of direction, though, and the field seemed to suck him under, and everything was black and wet and swirling, and he couldn't get his bearings, and then another round hit nearby, and for a few moments all he could do was hold his breath and duck down beneath the water.

Context Clue: Logic. Text says no sense of direction and everything was swirling and he couldn't get his bearings. That would suggest bearings would have to do with swirling and with all the chaos and explosion, it would seem it would be something like balance.

Original sentence: As I was going down the hill on my bike, I forgot to brake so I was losing my bearing and was about to fall.