A technique that I find useful for dealing with procrastination/lack of concentration/unpleasant situations is to consciously decide, then focus on, the next physical action. At my desk, I'll often clear distractions, then write it down on a post-it in front of me to help keep focussed.

The critical points are to decide before doing (not both at the same time), and make the action small and well-defined. E.g., "look up this person in the staff database and write down their phone number" as opposed to "get this person's sign off on project plan X". This allows me to focus on one thing, and not to be distracted, wondering if I'm doing the right thing or what to do next, while I'm doing it.

(I also use this to get myself up in the morning: "just switch the light on", "just pull back the duvet", ...)

eeph