There is such a range of meds called "tranqulizers". Broadly, ones ending in "zine" can be brutal on blood pressure, but some people have no trouble at all. They actually are old generation antipsychotics, but are often used to help people sleep because they aren't addictive. The ones ending in "pam" or "lam" are benzodiazepines and are used to help control anxiety and also sometimes sleep. The downside to them is that people become dependant.
I am a psych nurse, and must admit, was a bit worried about you when I heard you were being admitted, hoping your CFS Dr would set some parameters. Often the focus of a psych ward is to help people get activated and that goes against what we know about CFS. That being said, it might well be that your Dr wanted to try a slightly riskier medication (side effect wise) to see if you would get a benefit, and wanted you in a safe place when you took it. If so, kudos to your Dr for thinking outside the box.
I'm with Justy, sorry it didn't work out better, and hoping you are feeling some relief now.