If you lowered your AHI and you are still sleepy give it a little time. IF nothing still there are other factors that could make someone constantly tired in addition to sleep apnea. Vitamin D, Testosterone, and Iron deficiencies are all common sleepiness factors.

Appropriate levels of Vitamin D, Iron and Testosterone are common ways that people are tired outside of sleep apnea.

You can always try the digeredoo. I saw it on the Doctors. Also Vitamin D at appropriate levels will help you breath appropriately at night.

I generally have just a good dental mouthpiece for my backup. It is not as strong as the CPAP but eliminates my snoring and lowers my AHI.