First of all - Never assume that anyone who tells you anything actually knows what they're talking about. That person may even truly believe what they are saying and still be completely wrong. Also, some people will flat out lie to you. You absolutely do have a legal right to not have all your medical information disclosed to your wife. An exception would be if you were telling doctors or therapists that you were planning to kill your wife. Then they would have a legal duty to warn her.

Psych hospitals always have a conference room that is used as a make-shift courtroom, and they do hold legal hearings there, presided over by a judge, all the time. No doctor can just "have the court" commit you to anything. The judge is not a puppet of the doctor. The doctor merely offers his opinion to the judge. The judge gives that opinion due consideration, but does not blindly follow the recommendation of any doctor. The judge would also engage you in conversation and listen carefully to your concerns.