I'm afraid this sounds like 'star-gazing' due to IBD or other neuropathic virus. Symptoms can vary whenever a pathogen involves the CNS (brain/spinal cord). No one knows how loxocemus respond to IBD but in other pythons it can be fulminating (rapidly fatal).
The problem with shedding is related to the underlying pathology, in that a snake with neurological disease can not perform the coordinated movements required in the actual shedding process. And there is the potential that a snake could rub itself raw in spots (ie the head) attempting to shed, but the vast majority of snakes abandon trying to shed before this occurs. If you know for sure that the snake is ready to shed BUT CAN'T, then the keeper may need to manually shed the snake out, using a forceps around the head. A lox will fight this, but we all know snakes feel better after they shed.
I maintain my recently obtained juvenile lox on aspen shavings with the back 1" of the Phillips sweaterbox sitting directly on a strip of 3" flexwatt set at 95 F. All 3 specimens frequently will rest with part of their bodies directly over the flexwatt, particularly after a fuzzy mouse meal. Some may claim this is too warm, but you can't argue with a snake's behavior. The cool end of the cage is high 70's F. The front of the box develops some condensation, wetting the aspen. Sometimes they'll rest in the wetted aspen, and sometimes they hide in their box near the heat strip.
I think the respiratory symptoms in this snake are related to the underlying neuropathology and not to a 'typical' RI, although it can develop into one as a sequelae. Just blindly using an antibiotic is not usually beneficial in the long run. Certianly if the snake is showing the thick saliva of an active RI, I would advise getting a culture/sensitivity before starting any antibiotic.
I wish I could give you better news but there is always hope. I hope you'll b able to get this snake to a herp vet. Good luck!
Scott J. Michaels DVM