Behavior therapy assumes that behavior that has been learnt can also be unlearnt and vice versa. There are different forms of sexual behavior therapy: e.g the sex therapy of Masters and Johnson which assumes that people have sexual problems they haven't been taught to experience sexual behavior in a positive way. This means in general that people relearn at home how to make love by means of exercises in caressing, feeling and making love.
Another form of behavior therapy is the rational-emotive therapy (RET). This assumes that people with sexual problems have imaginary thoughts about a certain situation. For example: a man wants to get an erection when he makes love to his wife, but in advance he gets all sorts of disturbing thoughts: e.g 'I will probably fail again'. The therapist will make the person aware of these thoughts and will try to replace them by positive and arousing thoughts.
The psychosexual therapy of Kaplan: this therapy is a combination of sex therapy and psychoanalytic therapy.
Psychoanalytic therapy: this goes back to the past of the person. Negative experiences of the past and the corresponding feelings that haven't been dealt with may cause problems.
System therapy assumes that people in a relationship can influence each other in such a way that problems could arise or that sexual problems become worse. An example of this is a vaginistic woman who is being put under pressure by her husband to have intercourse.
In general it is important to get along with the social worker and that the method of treatment appeals to you.