The symptoms you describe, of too much cleaning and fear of dirt, are commonly found in people who have obsessive-compulsive disorder. Most such people have no other problems, but these symptoms can limit the persons life severely, and interfere with family relationships.
Psychologists treat obsessive-compulsive disorder with a talking treatment called Cognitive-Behavioural Treatment(CBT). Many treatment sessions may be needed, and the patient must be willing to cooperate.
Psychiatrists, who are medical doctors, usually prescribe medication. This works best if there is also counseling by the psychiatrist or some other mental health professional who is trained to do CBT.
Without treatment this disorder is not likely to get better, and symptoms often get worse if the person is under stress or pressure.