Not Enough Comfort [I Hug My Pillow While Sleeping]

I have been meaning to buy an additional pillow for bed. I've seen one you can put between your knees to help keep your back aligned so you don't keep turning over because your back aches. During sleep you are completely relaxed so it's your ribcage that stops the weight of your body from infringing on your breathing! Obviously in sleep state you breathe more shallow anyway and your heartbeat is slower too!