Starting my journey to better sleep - guidance appreciated

[StuffyNoseDude]

Summary
I fall asleep very quickly with no issues, and generally sleep soundly for about 5-6 hours. Been having a hard time with early wakeups ("sleep maintenance insomnia") for the last several years after about 5-6 hours of sleep. I thought it might be work stress, and it still may, but I have now begun believing it is physical. Sometimes I wake up hot but I've been blasting AC while I sleep so this is no longer the cause. 

My nose is always stuffy - it is manageable when awake, but when I lay horizontal and go to sleep my nostrils get quite stuffed. I use breathe right strips and elevate my head (two pillows and a mattress wedge). I also use saline spray (Ayr) in my nose before bed. On a sinus-related note, I often feel my ears are kind of stuffed up.

Lofta Sleep Test Results
pAHI = 4.7
pRDI = 24.0
min O2 = 89%
Slept terribly the test night. Also wore my breathe right strips and slept with head elevated, so it wasn't exactly a completely natural state, which perhaps made the results less severe than they would have been without these sleep aids that I use.

What I assume it is
UARS, based on the sleep test and waking up easily/not sleeping deeply (esp. after 5-6 hours, mostly REM phases). Also based on persistent sinus congestion. 

What works
Using half a Unisom pill (doxylamine 12.5g) will generally have me sleep through the night for 8-9 hours. This is a godsend but these antihistamines are not healthy long-term (alzheimer's risk) so I take them only when desperate.

What has not worked
Strict sleep hygiene, delayed-release melatonin, magnesium, CBD spray, zinc, theanine

What I have not tried yet
Aside from UARS, I have a hypothesis that maybe early AM cortisol is playing a role in early wake-ups. I am considering testing Ashwagandha or Phosphatidylserine as cortisol-reducing agents to see if that improves the early morning awakenings.

I also want to visit an ENT to get my nose checked out (septum, turbinates, jaw, etc.). I did see an ENT a while ago for something else and I think he said I might have a slightly deviated septum.

Why am I here?
If it really is UARS, then a CPAP could be helpful. I am here to ask for advice. The Lofta team is not helpful as they "don't diagnose UARS". They recommended an Auto-CPAP. Should I get an Auto-CPAP, a BiPap, a CPAP, or an ASV? What kind of mask should I start with? Do I need to go see an in person sleep doctor to try to calibrate or is the above enough to try to self-calibrate at home? Just general guidance for my situation. Is this likely UARS?

Thank you so much for being an awesome resource!

[StuffyNoseDude]

Bump...any advice? Is this UARS?

[Abrecaminos]

I don't have much experience only 5 years using CPAP. The questions you ask should be answered by your doctor, but you are very right to ask. Take my words just as an opinion.

What you have to find out is the cause of your flow limitation that produces arousals or that makes you not sleep deeply. UARS (Upper airway resistance syndrome) refers to the fact that the cause would be in your throat, and if the cause of the flow limitation is in your nose I have seen that they call it RERAs (respiratory effort related arousal).

Your study shows a good amount of RERAs (approx 19), plus some apnea/hypopnea (4.7 AHI).

I think it is good for you to start with an Auto CPAP to tackle at least your AHI. In my opinion, if the cause of your flow limitation is in your throat a CPAP could help you with your UARS and AHI, and if the cause it is in your nose it may not help you much with your RERAs.

Pay attention to your nose and talk to your ENT to know if you need treatment or surgery for sinus, allergies, deviated septum, turbinate reduction, etc. Decide carefully which machine to buy, perhaps you should start with an automatic CPAP which are the cheapest ones. 

If you have a bad nose a full face mask could help you (if you are a partial mouth breather).

[SleepyDawg]

I haven’t started my therapy yet, (waiting on my equipment), but I have been reading through the forum.  
I don’t know if your issue could be driven by the “chin drop” issue some have commented about, and the solution of using the soft cervical collars, (SCC).
I, too, wake up like clockwork between 4 and 4.5 hours after falling asleep, and almost always there’s a room temperature issue as a component.  Haven’t been able to figure out yet if it’s the OSA, or it could be environmental outside my house with the CSX train whistles, or still TBD.  
I take Ashwagandha in liquid pill form, but only in the AM so it does not interfere with sleep.  Mostly I take it as treatment for adrenal fatigue.  
I also have been following intermittent fasting schedule, (I only eat between 9AM and 5PM, thereby increasing the fasting phase to give body more time to repair cells.). Recently I have started tracking my last meal time to see if it is causing any interruptions in the sleep cycle, but I don’t have enough data to analyze that yet.