My husband calls my fear like that, not having an "I don't know" bucket It helps me when I get anxious because I do not understand (yet :-) to remember and think of that way of "containing" the fear. Maybe you can come up with a container with yours and instead of staying stuck thinking about and feeling it, put it in the container and put the container aside so you can go back to functioning. Think of putting it in a freezer or something?