Why He Was A Total Asshole:
More like Sigmund Fraud. (We're the first to make this joke, don't look it up.) For starters, he would lie about patients being cured or fudge facts about his cases to "prove" his points, and then conveniently burn his original notes, leaving little evidence of his trickery. For instance, he once wrote about a patient, the Wolf Man (not his legal name), remembering something which confirmed Freud's theory about the origin of his dreams. But when a journalist later tracked the patient in question down, the guy essentially said, "LOL no."
Not all of Freud's patients left his office with the same problems they had when they came in, though. Some left with even more. One patient, "Dora," was a victim of unwanted advances whom Freud accused of actually being, like, super into it (and her dad) and in denial. Probably the worst instance of this was the case of Horace Frink, whom Freud instructed to divorce his wife and marry another patient, who herself was married. Frink and the other patient did so, but eventually realized this wasn't such a bright idea, and Frink never recovered from the stress. His new wife started to look like a man or a pig to him.
Freud offered this helpful (and grammatically appalling) tidbit: "Your complaint that you cannot grasp your homosexuality implies that you are not yet aware of your fantasy of making me a rich man let us change this imaginary gift into a real contribution to the Psychoanalytic Funds." Very smooth. Frink ended up having to be committed to a mental hospital, which you might recognize as usually the exact opposite of a therapist's goal.