It is not unusual for the process of change to take 5-10 years. This is no reason to despair. Many people change their identity much sooner than this. Significant relief from the intensity of homosexual feelings can also come much sooner. As with any deep personal issues which a person may want to change, there are no guaranteed results.
Many people do experience a complete change of sexual orientation.
Where before they were only attracted to the same sex, they are now only attracted to the opposite sex. Other people experience significant progress toward that goal. They may now be fully attracted to the opposite sex and ready for marriage, with very little same-sex attraction remaining. For others, there may be great change in their attraction toward the opposite sex without any change in their attraction to the same sex. Others still may become able to make healthy choices in terms of their behaviour yet find that their attractions and desires remain the same.