It is entirely possible to have unwelcome thoughts hovering around in your head and still attend to your current responsibilities. People do it all the time. It may be frustrating, but enduring frustration goes with being a grown up.

If I keep telling myself to not think about a pink elephant, I'm going to keep thinking about a pink elephant. Long ago I received good advice when I was grieving a loss. A family member told me that the human mind can't really think about two things at once. He said that, if I get my mind busy with something that absorbs my attention, I will temporarily lose consciousness of my sad, distressing thoughts . . . at least for a while. That's one of the smartest things anyone ever told me. I forget, some times, to put it in practice. But, when I remember and do it, it works.