I too have a CPAP and have been using for close to 20 years now. This device is fantastic and really gave me my life back. I do not use the humidifyer and let it start full force, rather than the gradual build up. Make sure to change your filters regularly and clean your mask and elestic band at least monthly.
Sounds like you have a faulty device or perhaps it is just not for you. Check with your doctor and/or supplier.