Kimberly Johnson was voted "woman most likely to rule the world" when she was a high school senior. "I was a tough babe," she recalls, "attractive and bright and hip and extremely outspoken."

Several months ago, unable to get to work on time, convinced that people saw her as "a poor little rich white girl," she was laid off from a $8,700- a-year job at a government library. Lately, Johnson has stayed in her Connecticut Avenue apartment, collecting unemployment and denigrating herself for being ill.

"I feel like an old person now," says Johnson, 31. "Like those characters in Shirley Jackson stories: nondescript women in huge cities, doing nothing, going nowhere, having no one. It makes me hate myself."

Johnson, a thin, attractive woman meticulous in her dress and makeup, has been diagnosed at the D.C. Institute of Mental Hygiene as having "a borderline personality disorder with hysterical and depressive features."

Dr. Harold Eist, who made the diagnosis and who supervises her treatment (though he is not her therapist) believes "something went awry" in Johnson's childhood, probably in her relationship with her mother. Johnson remembers when she was 3 and 4 years old her mother poked her fingernails in her arms, pulled her hair and locked her in her room.

As a result, Eist says Johnson grew up with a personality disorder--"a primitive, lumbering coping apparatus." He compares her to a thermostat that needs a hundred different settings but has only two.

She speaks of herself as either a "near genius" or a fool, a "tough babe" or a pitiful mental patient, a slender young woman or a "fat hog." She spends hours in front of a mirror to make sure she hasn't suddenly turned ugly.

Johnson grew up in affluent Washington suburbs. Her father was a high-level government administrator, her mother an artist. "I wasn't raised to be poor. I'm really aware that I'm descending," Johnson says.

In college, she found herself cowering in her dormitory room, unable to speak, wondering what people were saying about her. She quit, came home for six months, then took off for four years. When a boyfriend broke up with her in 1972, she had a breakdown.

"I knew when I hit bottom I would never recover . . . I still feel to this day that I am kind of dead. I didn't talk for almost two years. I almost didn't move. I was frightened all the time. I never laughed. As time went on people didn't want to see me."

She returned home and went to bed. "My brother stormed in the room one time. He said, 'Look at you. You get out of that bed.' And I couldn't tell him what was the matter because I didn't know. I knew I was different, and it broke my heart."

Johnson found a low-level federal job, but lost it when she tried to "punch my supervisor's face in." She was hospitalized at George Washington Hospital and saw a private psychiatrist. In the mid-'70s, her parents stopped giving her money. Through a friend, she heard about the institute. She has been going there for nearly six years, paying $5 a session to see a psychiatric social worker three times a week.

Johnson says she has learned that she is unable to handle separation or affection. Eist, who sees Johnson once or twice a month, gives her Nardil, an antidepressant, and Valium. She says they keep her calm enough to take care of herself and learn from therapy. Johnson says she has been told it may take 10 years or more of psychotherapy before she can live on her own.

Popular neo-Freudian the ories about personality disorders assume that infants, responding to inconsistent or cruel mothers, develop a "false self" to cover up their injured "true self." Therapy theoretically can strip away the false self and strengthen the true one.

Johnson doubts this can work with her. She wonders if she should quit therapy. Two years ago, she tried est assertiveness training. She's looked into megavitamin therapy. She's read the work of Thomas Szasz, who claims that mental illness is a myth, and of R.D. Laing, who claims it is the response of a sensitive person to a chaotic world.

"Therapy is always baffling to me," says Johnson. "Half the time, I think they (her therapist and Eist) don't know what they are talking about." But she keeps coming to the clinic. Eist and her therapist, she says, are her best friends.