Hey Ezz,
Sometimes I use DH as my pillow, draping my leg over him instead of having the pillow in bed. He can't fall asleep with me touching him so we usually snuggle for a while and then I grab the pillow.

As for the sleeping on the back issue, the physio at the hospital said it was fine if you are not waking in pain. She said she slept on her back her whole pregnancy as that was comfortable, so don't stress if you wake up on your back. Like the others said, I use a pillow under one side (of my bottom ) and it kind of makes me lean over a bit, which is more comfortable.

Good luck!