Please get this checked out. I spent decades of my life dragging due to sleep apnea before getting it diagnosed. And it's really not good for your brain, as well as poor sleep being generally bad for your health & work. I do have a CPAP machine but it's a mission to use. The important thing is to keep the airway open while sleeping. I'm side sleeping now using a certain pillow. But your situation seems worse than my very mild case. Whether it's sleep apnea or not, it may help you to get it checked out.
I don't remember the company I got it from, but I did find it online at amazon: https://www.amazon.com/Sleep-Innovations-Contour-Memory-Warranty/dp/B006JQ48JI/ref=pd_lpo_vtph_121_tr_img_2?_encoding=UTF8&psc=1&refRID=MGFHGM9Z8Q2HBY7MX419 It seems expensive, but would be totally worth it, and there is always a chance another website would have it for cheaper.
I bought this one many years ago: https://www.amazon.com/gp/product/B006JQ48JI/
It's spendy, but it's lasted for years and seems like it will for many more.