You need to get him a hot spot of around 90F or at least get the ambient up to around 86F. Anything below 75F with no access to a warm 86F+ spot is going to give you problems. As for his open mouth breathing and misaligned jaw, I would guess probably either RI or mouth rot. It probably isn't IBD as IBD is quickly fatal in pythons so if he had it, he would be dead in a couple days. Best advice I can give is get your temps and humidity squared away and take him to the vet. Best of luck.