What can I do to stay on my front (positional apnea due to large tongue)?

[aplacelikethis]

Whenever I sleep on my back or partially on my back, I have terrible sleep and wake up after 3-5 hours every single night. Because of this, I've transitioned to sleeping on my front. I cradle a long pillow with my left hand to tilt my body away from the bed in order to relieve strain from my neck. 

What can I do to prevent myself from rolling onto my back while asleep? I'm planning on trying to wear a backpack stuffed with a pillow tonight.

Here's the data attached. 


Mask: F&P Vitera

[G. Szabo]

See the "Side sleep enforcer for positional apnea" and the "Fixed Sleeping Position the entire night?" posts.