Make it a project (or a couple of projects). Define them in terms of outcome 'decision about X's renumeration has been made and communicated'. 'New team member is on board'. What is your very next action. What is its context. Write that on your next action list.
Do you need to make an appointment with HR? review X's last performance appraisal? Update the budget for X's team? Talk it over with one of you co-managers if you have one? when something is really bugging me I find often I am missing a piece of information, or just need to talk to somebody. Mind mapping or otherwise following the natural planning model will help figure out what that is.
when I am worried about something I also find it helps to get even more granular than normal for my next action - I'd go down to the level of "retrieve copy of X's performance appraisal". record that on your @office or @computer next action list. No matter how much anxiety is causing procrastination you WILL be ale to do an action like that, and even having made that decision will make you feel better.