I've seen SpO2 desaturation of around 60% during severe episodes, the brain detects the change in O2 & CO2 concentrations and rouses the body from sleep for the signature momentary gasping events. So it's quite unlikely that a person would suffocate because your brain and body don't won't to die so they react to prevent it, even when you're unconscious.

Far greater concern is the CO2 accumulation that can occur due to hypoventilation (reduced exchange of gasses via inspiration/expiration).

As CO2 concentration increases so too does the acidity of the blood and other body fluids. While awake there is always the opportunity for deliberate intervention by breathing deeper or faster, but while asleep the process is more of a mechanical homeostatic one with intervention only when certain critical thresholds are crossed. The gasping episodes provide only a brief reprieve from the accumulation, the balance in Ph changes to varying degrees but soon after the trend returns, and the cycle repeats. This can eventually lead to tissue damage, particularly heart muscle among other things. It can also contribute to fatigue, stomach issues, headaches, diabetes, and has impact on Ghrelin and Leptin, two hormones that help regulate metabolism (meta analysis here). This can be a particularly cruel blow to those for whom body mass is a contributing factor to their AHI as the fatigue and metabolic factors compound each other, making it all the harder to reverse.

It's worth pointing out the CPAP & BPAP typically don't supply Oxygen without specific coexisting conditions, these devices simply compress air from the room in which they're operated and deliver it to the user to 'inflate' the soft tissues of the upper airways, mitigating some of the obstruction. Any loss of pressure, such as through the nose or mouth, will reduce the effectiveness.

It's good of you to share this personal experience and insight with others, and to not only point out that diagnosis and intervention may be partially or fully funded under a regional health scheme, but also the contributing factors. The reason I say this is: too many times I've seen an individuals energy and outlook improved by CPAP or BPAP, only to watch them commit with renewed enthusiasm the behaviours that contributed significantly to their condition.

For some conditions CPAP/BPAP are a lifelong association, but for most they are a bridge, an intervention tool, something to give one the best shot at getting stronger and healthier. The other main ingredient, like with many things, is ones self.

You seem very motivated, you'll do quite well.