I'm not actual doctor and there can be better ways to threat your problem, but here are two things that helped me greatly with quality of sleep.
First of all buy yourself high-quality CO2 meter for ~$100 and make sure that CO2 not going over 1000 PPM while you sleeping. Every single time I sleep in closed room with bad ventilation where CO2 getting over 1200-1500 PPM I will wake up in terror. You can't imagine how many people I knew had terrible quality of sleep due to bad ventilaton and never realise it.
Second thing if nothing else works. Try strictly-scientific lucid dreaming practices: record as much of dreams is possible in a diary for several months, do deep breathing before sleep, etc. Looking at your hands every now and then is required and slightly weird, but it totally worth it. Once you get lucid in a dream once and preserve memory of it will become much easier to deal with nightmares.
Lucid dreaming cost nothing even though some REM sleep tracker like one in Apple Watch is useful. Though beware of bullshit.
I've been living in both nothern country where people dont tend to open windows because it -10C outside. And I also lived in SEA where expats literally live with windows constantly closed and conditioner on all due to high temperature and humidity.
I guess in US owner of 150+ m2 / $500,000+ house will never have problems like bad ventilation, but people with worse living conditions and small appartments certainly can certainly have such issues.
I found some studies from OSHA (the United States gov't agency) about very high carbon dioxide levels in certain industry settings, such as where dry ice is used. Effects on cognition are significant at high levels.
But understanding the effects of CO2 in more every day situation seems more complicated. It is also hard to find good rules of thumb about guidelines about when to look more deeply and pay to get measurements.
But I haven't found high-quality studies that talk about residential settings. My Google results seem to be populated with companies trying to sell stuff. So based on maybe 30 minutes of research, I remain practically skeptical.
I'm interested in learning more, Starting with the chemistry and airflow (?) properties of CO2, and then working up to biology. Would you mind sharing high-quality resources you recommend?
Just google something like "Acceptable CO2 Levels in Commercial Buildings" or check out UK government website on hazards of CO2. [1]
I personally might be more sensetive than others, but real issues start when PPM going over 2000. Two sleeping people in small room with bad ventilation can easily bring it as high as 2500 in 3-4 hours.
Also if you're cooking on gas in small appartment and have bad ventilation you can easily bring it to 3000-4000 in much shorter period of time.
First of all buy yourself high-quality CO2 meter for ~$100 and make sure that CO2 not going over 1000 PPM while you sleeping. Every single time I sleep in closed room with bad ventilation where CO2 getting over 1200-1500 PPM I will wake up in terror. You can't imagine how many people I knew had terrible quality of sleep due to bad ventilaton and never realise it.
Second thing if nothing else works. Try strictly-scientific lucid dreaming practices: record as much of dreams is possible in a diary for several months, do deep breathing before sleep, etc. Looking at your hands every now and then is required and slightly weird, but it totally worth it. Once you get lucid in a dream once and preserve memory of it will become much easier to deal with nightmares.
Lucid dreaming cost nothing even though some REM sleep tracker like one in Apple Watch is useful. Though beware of bullshit.