be lost without (someone or something)
To be helpless or unable to function without someone or something. Ever since Mom died, I just feel like I'm lost without her. When it comes to repairing things, I'm usually lost without instructional videos. I'd be lost without my assistant—she's the only one who keeps my crazy life remotely organized.
be/feel ˈlost without somebody/something
feel unable to work or live without somebody/something: I left my watch at home and I feel lost without it.I’m completely lost without my diary.