I've also been struggling recently. Also confuses me since I'm not big yet.
It was my hips that were killing me so I tried the pillow between the knees. That worked for a few days now it makes no real difference

but it's not every night. Only some nights I'm haunted by pains in my hips. It does help having a pillow under my belly though.
What I've found works is lying on my back at an angle. But staying in that position isn't easy for long.... it depends on how long DH is willing to have my knees on his back/stomach.