Depending on your general, at rest, oxygen saturation and the position you sleep, it is possible that you could try the "blow-by"technique at night. I do this for infants and children all the time.
Simply use a nebulizer attachment instead of the cannula and clip it to your pillow, ensuring it literally "blows by" your face. Please talk with your pulmonologist first as lack of oxygen is obviously a bad thing. ; ) It may not be a high enough concentration at that point, without knowing your medical history.
There are also products on the market that securely fasten to your head instead of over the ears with the sliding band under your chin. They have not been proven any more effective, yet, so are not covered by most insurance as of now. Alot of foks simply put the sliding band behind their head, then sleep on their side, but you then run the risk of obstructing airflow through the tubing. Again, discuss with your doctor since he/she will most likely have a few suggestions as well.
Good luck and I hope it gets easier for you soon.