I've had the same problem sleeping with a CCF mat on the ground, as I'm a natural side sleeper. In fact, I'm never really comfy on the ground, no matter what mat I use. But it works quite well in a hammock, whether you sleep on your back or on your side. You already have your gear and probably won't want to make changes at this point. But no one has mentioned hammocks yet it this thread, so I thought I'd chime in.