Seriously, stop reacting.
Stop checking Twitter, Facebook, email and anything else that's driven by notifications. In fact just turn off all notifications. Turn them off on your computer, phone and tablet. Notifications are the great reactive intruder that ruins your focus. With notifications turned off, you'll stop reacting to the outside forces that will destroy your focus.
Stop putting the work aside that should be doing for the work you need to do. Yes there are things we need to do, but we should be smart enough to identify the work we need to do and schedule it in for the appropriate time in the future. It then becomes work we should be doing at the right time. Continually reacting to work that needs to be done shows a lack of planning. Plan ahead to eliminate reactive work.
Stop reacting aimlessly to changes in your life. Aim for a point in the distant future and work towards it. The world will do it's best to try and push you off track. Changes in family, career, finances and health can be negotiated with a slight detour but you can still arrive at the place that you initially aimed for.
Stop reacting. It can be done.