I had a particularly bad day once last year when I started taking Prednisone AND Zoloft on the same day. Talk about a bad trip!! I was twisting and turning in the hospital bed all day with hallucinations, panic attacks, etc. The next day everything went back to normal and I should add that Zoloft has been a life safer. The problem was the interaction between the 2 starting on the same day.
Other than that, my worst days at the hospital, in general, are when I start reaching a point when I'm fed up of having my privacy invaded every 10 minutes (about 5 days in), and/or a day where things don't go as planned, for instance if they decide to draw blood from my artery when the doctor told me that would not happen anymore. Inconsistencies (while hospitalized) make me super stressed out.