I had to go to and appt last week that I desperately wanted to cancel. In the end its just a case of doing what we need to. It is the waiting that is that hard part. Can you get a friend to go with you? Maybe have a cuppa beforehand to settle into the area?
Please be careful taking old ativan (or any old meds) as they make affect you differently than you expect them to.
In the mean time try and keep your mind occupied with other things.
Take Care.