大神们，请教一下，（英语周报完型）

I was cooking dinner when my cell phone rang. My friend Anna called because her car broke down and her two kids were hungry and tired. She asked if I could go and fetch the kids while she was waiting for the car service.

I asked my husband to take over cooking dinner and then started my car. As I was driving to my destination, fog formed and thickened. After picking up the kids, I had to drive in thick fog.

The children were my responsibility and I couldn't help but be _____.

这里答案给的是nervous，can't help but do翻译成“禁不住”；想请教一下，有些同学将can't help but 翻译成“不得不；只得……”这时候感谢应该选另外一个选项patient。请问选patient 为什么不行？