The best treatment available to manage obstructive sleep apnea
(osa) is cpap. You are using it for 3 years now, itself is an indication that you feel benefit by using it, so why do you want to leave it and try other therapies, which are usually not very effective for osa. Not taking treatment for osa for a long time can have detrimental effects on health. I suggest you keep using your cpap machine, and also get
evaluated periodically with your sleep specialist for seeing the latest situation of your condition and pressure changes that may be required if any.