Not too much information; thanks for lead on colloidal silver and good luck with your surgery.
One point about sleeping on your back. I, too, sometimes have trouble with my breathing and my throat seeming to close and sort of gagging. I find that lying with my head as low as possible is better than propping it up, forcing the chin towards the chest. The idea is to rotate the head in the other direction thereby opening up the throat. The most extreme would be to use no pillow, but I prefer to just sort of punch it around to get some support under my neck but still have the head back and down as much as possible. The only other way I think I could do it is in a recliner, but that doesn’t seem to be an option for you. But, yeah, you need to do your research ahead of time and find something that works. If you can’t get comfortable enough to sleep at least some, it’s going to be a tough row to hoe.