Hypoventilation/Hypoxia due to Pinched Nerves

My Oxygen Level will drop to 70% or below on the Pulse Oximeter when I lay flat on my back (quite often) or my right side(infrequently). I have T12, L1, L5 compression fractures, Degenerative Disc, Stenosis, Scoliosis and take a sedating neuroleptics for TBI issues. Help with this is appreciated, I for example will lay down to use the phone or read a book, forget about the condition and roll flat on my back, black out and drop the phone or my book onto my face. Or the floor or behind the bed …….