Hello Jen. Welcome!
Getting started with CPAP can seem overwhelming at first, but it gets easier as you go. It is mostly a matter of trial and error to find what works best for you.
I would like to share a few things that have helped me get my mouth leaks under control when I first changed from a Full Face Mask to my P10. By changing to the nasal pillow I went from fighting large leaks most nights to very rarely having a large leak.
Is your chin strap properly fitted? I find mine needs to be as tight as possible without being uncomfortable. Where the chin cup rides can also make a difference. I find the strap will pull my jaw back allowing my mouth to fall open unless the strap fits under my jaw instead of around my chin. Some people find they have to do exactly the opposite to achieve the best results.
One of the forum members has developed a technique she calls the "Tongue Suck Technique" that a lot of members find useful. By using her technique a lot of people are able to learn control their mouth leaks without a chin strap. I haven't mastered the technique well enough to eliminate the chin strap, but it does help.
- Place the tip of your tongue on the base of your front teeth.
- Place the base of your tongue against the top of your mouth.
- Create a slight suction in your mouth and hold it.
For some people it becomes second nature and is all they need to eliminate mouth leaks.
I have found that on nights that it seems that no matter what I do my mouth leaks, I can shove a pillow up under my chin and cuddle it to hold it in place. This adds just enough resistance to keep my mouth from opening. I have also found it useful to put my P10 on, get it adjusted and then put my chin strap on over the the P10. This makes the mask much more stable and helps keep the P10 straps in place.
Other members have found they can control mouth leaks by wearing one of the soft foam cervical collars you can get at pharmacies and online.
As for your high AHI, it may be helpful if you download the free SleepyHead software and post some charts so the experts on the board can look at them and give you some tips on what is actually going on and on how to solve any issues you may be having. You can find links to the software in my signature below or at the top of the page. Also be sure to sleep on your side and not your back. Sleeping on your back tends to cause apnea events and raise AHI numbers.
Good luck on your treatment.