lose one’s grip
lose (one's) grip on (someone or something)
1. To no longer have a firm or secure grip on someone or something with one's hand or hands. He lost his grip on the railing and went tumbling down the stairs. The rescue team is almost here—don't lose your grip on him!
2. To no longer have a firm or clear understanding of something. The poor guy sort of lost his grip on reality after the death of his children. I feel like I'm losing my grip on my sanity.
lose one’s gripand lose one’s hold
tv. to lose one’s control over something. When I begin to lose my grip, I will just quit. The old man is clearly losing his hold.