Have you been diagnosed as having OSAS. Only then would CPAP machine help you. Also i think you do have OSAS and are not having relief with the present treatment then you should undergo a repeat polysomnography
ideally a split night titration study that would tell about the present Sleep Apnoea index and also find the optimum settings to relieve your apnoeas. Many a times obstructive apnoeas are associated with central apnoeas so continue with medicines meanwhile. Please discuss these issues with your sleep physician.