You can get extra long o2 tubing so that you can put the machine in another room, cuts down on the noise as well, so DH may sleep better. Also, the machine with its warm air is probably drying the air out in your house. That would be causing the sore throats. You can boil some water on the stove to add some humidity back, buy a humidifier, or use saline nose spray/drops, which will moisturize your oropharyngeal area.
Best of luck!