lose (one's) bearings
To lose sight of or become unable to determine one's orientation, position, or abilities relative to one's surroundings or situation. Trying to find her way home through the woods in the dead of night, Sarah lost her bearings when the clouds obscured the stars overhead. I feel like I've been losing my bearings in life ever since I lost my job.
lose one's bearings
see under get one's bearings.