Klonopin! I have anticipatory anxiety... so I assume the worst before it's happened. My therapist gave me a great coping strategy and that is to answer my "what ifs"
For example: I used to panic and think that the answer to everything was that I was going to die...
what if my son doesn't sleep all night?! Then I would move on to the next source of panic instead of answering this, building up my anxiety.
Proper Answer: well I guess he'll be tired and grumpy and so will I.
It makes much more sense when I can verbalize this. But rationalize with yourself instead of assuming the worst!