That would make sense. I wonder if, laying on the stomach is actually freeing the phrenic nerve, allowing the diaphragm to work better, and therefore providing more oxygen.
Actually I had to devise most of this myself as I've had a physical & mental, disability that was getting worse and worse with no cure or useful treatment. I'm writing things up at the moment, basically an explanation of how muscular imbalances lead to brain and nerve dysfunction causing (possibly explaining, depression, anxiety and a whole lot of other things) and what to do about it.
I should be able to share in a few weeks, if you're interested can you send me a message twitter.com/shardinator and I'll send you an early copy. Else I'll post something here when it's a little more fleshed out.
Massage under the mastoid process of the temporal bone. This will release pressure on your Limbic System in general, improving your emotional connection to the world, and in particular will let your Amygdala to settle reducing your sense of fear, in turn making you a more joyful and open person. Long term you want to find a way to strengthen and balance your Deep Neck Flexors and Deep Neck Extensors, however how to do that effectively is a very open question.
I might be able to help with the car accident injury. I had a rear-end car accident 11 years ago. I know the pain/suffering. It's like nothing you can imagine till you have it and then it never goes away, worst of all no professional knows what to do about it.
The last two years I've read pretty much everything and contacted every researcher/research group working on this. They have some good material, but eventually I had to adapt their work into my own techniques. I'm now about 80-90% fixed and in a few months I think I'll be all good.
I've developed an exercise program along with an elastic head sling that supports and strengthens the neck. If you're interested DM me on twitter https://bit.ly/2LTVMMl and I'll send you some info about how I did it, you might have to modify some things but I think the basic ideas will apply.